path: root/X11R6.mdwn

<div itemscope itemtype="http://schema.org/SoftwareApplication">

# <span itemprop="name">X Window System</span>, <span itemprop="version">Version 11, Release 6</span>

<span itemprop="description">
X11R6 was the sixth release of the X Window System, Version 11.
</span>
It was released in
<span itemprop="datePublished" content="1994-05-16">May 1994</span>,
with the following changes excerpted from the <a href="http://www.x.org/releases/X11R6/RELNOTES.TXT" itemprop="releaseNotes">release notes</a>.
The sources are available for download for historical reference from
<a href="http://www.x.org/releases/X11R6/" itemprop="downloadUrl">http://www.x.org/releases/X11R6/</a>.

[[!toc levels=4 startlevel=2]]

## What Is Release 6

This is the 6th release of X Window System software from  [[the X Consortium|XConsortium]].  X is
a network-transparent window system which runs on a wide range of computing and
graphics machines.

The X Consortium is an independent, not-for-profit corporation, the successor to
the MIT X Consortium, which was part of the MIT Laboratory for Computer Science.

### Overview of the X Consortium Release

There are two parts to Release 6: X Consortium software and
documentation, and user-contributed software and documentation.
The X Consortium part contains the following:
<dl>
<dt>X Consortium Standards</dt>
<dd>The X Consortium produces standards: documents which define network
   protocols, programming interfaces, and other aspects of the X environment.
   See the <i>XStandards</i> manual page for a list of standards.</dd>
<dt>Sample Implementations</dt>
<dd>For most of our standards, we provide <i>sample</i> implementations to
   demonstrate proof of concept.  These are not <i>reference</i>
   implementations; the written specifications define the standards.</dd>
<dt>Fonts</dt>
<dd>A collection of bitmap and outline fonts are included in the
   distribution, contributed by various individuals and companies.</dd>
<dt>Utility Libraries</dt>
<dd>A number of libraries, such as the <i>Athena Widget Set</i>, are included.
   These are not standards, but are used in building X Consortium applications
   and may be useful in building other applications.</dd>
<dt>Sample Programs</dt>
<dd>We also provide a number of application programs.  A few of these programs,
   such as <i>xdm</i>, should be considered essential in almost all
   environments.  The rest of the applications carry no special status; they are
   simply programs that have been developed and/or maintained by X Consortium
   staff.  In some cases, you will find better substitutes for these programs in
   the user-contributed part.</dd>
</dl>

The user-contributed part contains whatever people contribute.  You'll find a
variety of software and documentation here: programs, demos, games, libraries, X
server extensions, etc.

### Supported Systems

We built and tested this release on the following systems:

 * A/UX 3.0.1
 * AIX 3.2.5
 * BSD/386 1.0
 * HP-UX 9.1
 * IRIX 5.2
 * Mach 2.5 Vers 2.00.1
 * Microsoft Windows NT 3.1
 * NCR Unix System V Release 4/MP-RAS
 * NEWS-OS 6.0
 * OSF/1 1.3
 * OSF/1 1.0
 * SunOS 4.1.3
 * SunOS 5.3
 * UNICOS 8.0
 * UNIX System V/386 Release 4.2 Version 1
 * Unix System V/860 Release 4.0 Version 3
 * Ultrix-32 4.3

On NT, most of the release builds with the Microsoft SDK.  Missing are
<i>Fresco</i>, <i>twm</i>, <i>xterm</i>, <i>xdm</i>, <i>xconsole</i>,
<i>xinit</i>, <i>xhost</i>, <i>xsm</i>, and the X server.  Xt, Xaw, and Xmu
libraries are not built as DLLs.  Imake works, albeit with some restrictions.

### The XC Tree

The first thing you may notice is that you can't find anything.  The source tree
has undergone a major reorganization since R5.  The top-level directory has been
renamed from <b>mit/</b> to <b>xc/</b>.

The general layout under <b>xc/</b> is now as follows:

<pre>
config/         config files, <i>imake</i>, <i>makedepend</i>, build utilities
doc/            all documentation other than per-program manual pages
fonts/          BDF, Speedo, Type1 fonts
include/        include files shared by multiple directories
lib/            all libraries
nls/            localization files
programs/       all programs, including the X server and <i>rgb</i>
test/           X Test Suite and other test suites
util/           <i>patch</i>, <i>compress</i>, other utilities
workInProgress/ snapshots of work in progress
bug-report      bug reporting template
registry        X Registry
</pre>

#### config/

The <b>xc/config</b> directory now has subdirectories:
<pre>
config/cf/          all the config files: Imake.tmpl, Project.tmpl, etc.
config/imake/       the <i>imake</i> program
config/makedepend/  the <i>makedepend</i> program
config/util/        other configuration utility programs and scripts
</pre>

#### lib/

Xlib sources are in <b>xc/lib/X11</b>; we've renamed directories to match the
lib<i>name</i>.a names.

#### doc/

<pre>
doc/specs/      X Consortium standards and other specifications
doc/man/        manual pages for libraries and general manual pages
doc/util/       macro packages and utilities for formatting
doc/hardcopy/   PostScript versions of the documentation
</pre>

The <b>xc/doc/hardcopy</b> directory contains compressed, pre-formatted
PostScript versions of documentation elsewhere in the <b>doc</b> tree and the
program manual pages, which are in each program's source directory.  These files
can be uncompressed with the <i>compress</i> program, which is included in
<b>xc/util/compress</b>.

#### extensions

There is no longer a top-level extensions directory.  Extension libraries
are now under <b>xc/lib/</b>, server extension code is under
<b>xc/programs/Xserver/Xext/</b>, and extension header files are under
<b>xc/include/extensions/</b>.

### Extensions supported

The core distribution includes the following extensions:
BIG-REQUESTS,
LBX,
MIT-SHM,
MIT-SUNDRY-NONSTANDARD,
Multi-Buffering,
RECORD,
SHAPE,
SYNC,
X3D-PEX,
XC-MISC,
XIE,
XInputExtension,
XKEYBOARD,
XTEST, and
XTestExtension1.

### Implementation Parameters

Some of the specifications define some behavior as implementation-dependent.
Implementations of X Consortium standards need to document how those parameters
are implemented; this section does so.

<dl>
<dt>XFILESEARCHPATH default</dt>
<dd>This default can be set at build time by setting the <i>imake</i> variables
   XFileSearchPathDefault, XAppLoadDir, XFileSearchPathBase, and ProjectRoot in
   <b>site.def</b>.  See <b>xc/config/cf/Project.tmpl</b> for how they are used.

   By default, XFILESEARCHPATH has these components:
      /usr/X11R6/lib/X11/%L/%T/%N%C%S
      /usr/X11R6/lib/X11/%l/%T/%N%C%S
      /usr/X11R6/lib/X11/%T/%N%C%S
      /usr/X11R6/lib/X11/%L/%T/%N%S
      /usr/X11R6/lib/X11/%l/%T/%N%S
      /usr/X11R6/lib/X11/%T/%N%S
</dd>
<dt>XUSERFILESEARCHPATH default</dt>
<dd>If the environment variable XAPPLRESDIR is defined, the default value
   of XUSERFILESEARCHPATH has the following components:

      $XAPPLRESDIR/%L/%N%C
      $XAPPLRESDIR/%l/%N%C
      $XAPPLRESDIR/%N%C
      $HOME/%N%C
      $XAPPLRESDIR/%L/%N
      $XAPPLRESDIR/%l/%N
      $XAPPLRESDIR/%N
      $HOME/%N

   Otherwise it has these components:

      $HOME/%L/%N%C
      $HOME/%l/%N%C
      $HOME/%N%C
      $HOME/%L/%N
      $HOME/%l/%N
      $HOME/%N
</dd>
<dt>XKEYSYMDB default</dt>
<dd>Defaults to <b>/usr/X11R6/lib/X11/XKeysymDB</b>, assuming
   <b>ProjectRoot</b> is set to <b>/usr/X11R6</b>.</dd>
<dt>XCMSDB default</dt>
<dd>Defaults to <b>/usr/X11R6/lib/X11/Xcms.txt</b>, assuming
   <b>ProjectRoot</b> is set to <b>/usr/X11R6</b>.</dd>
<dt>XLOCALEDIR default</dt>
<dd>Defaults to the directory <b>/usr/X11R6/lib/X11/locale</b>, assuming
   <b>ProjectRoot</b> is set to <b>/usr/X11R6</b>.</dd>
<dt>XErrorDB location</dt>
<dd>The Xlib error database file is <b>/usr/X11R6/lib/X11/XErrorDB</b>, assuming
   <b>ProjectRoot</b> is set to <b>/usr/X11R6</b>.</dd>
<dt>XtErrorDB location</dt>
<dd>The Xt error database file is <b>/usr/X11R6/lib/X11/XtErrorDB</b>, assuming
   <b>ProjectRoot</b> is set to <b>/usr/X11R6</b>.</dd>
<dt>Supported Locales</dt>
<dd>For a list of locales supported, see the files <b>locale.dir</b> and
   <b>locale.alias</b> in the <b>xc/nls/X11/locale/</b> directory.</dd>
<dt>Input Methods supported</dt>
<dd>The core distribution does not include any input methods servers.  However,
   in Latin-1 locales, a default method that supports European compose
   processing is enabled.  See <b>xc/nls/X11/locale/Compose/iso8859-1</b> for
   the supported compositions.  There are input method servers in contrib.</dd>
</dl>


## What Is New in Release 6

This section describes changes in the X Consortium distribution since
[[Release 5|X11R5]].  Release 6 contains much new functionality in many areas.
In addition, many bugs have been fixed.  However, in the effort to develop the
new technology in this release, some bugs, particularly in client programs, did
not get fixed.

Except where noted, all libraries, protocols, and servers are upward compatible
with Release 5.  That is, R5 clients and applications should continue to work
with R6 libraries and servers.

### New Standards

The following are new X Consortium standards in Release 6.  Each is described in
its own section below.

 * X Image Extension
 * Inter-Client Communications Conventions Manual (update)
 * Inter-Client Exchange Protocol
 * Inter-Client Exchange Library
 * X Session Management Protocol
 * X Session Management Library
 * Input Method Protocol
 * X Logical Font Descriptions (update)
 * SYNC extension
 * XTEST extension
 * PEX 5.1 Protocol (released after R5)
 * PEXlib (released after R5)
 * BIG-REQUESTS extension
 * XC-MISC extension

### XIE (X Image Extension)

The sample implementation in Release 6 is a complete implementation of full XIE
5.0 protocol, except for the following techniques that are excluded from the SI:

<pre>
ColorAlloc:     Match, Requantize
Convolve:       Replicate
Decode:         JPEG lossless
Encode:         JPEG lossless
Geometry:       AntialiasByArea, AntialiasByLowpass
</pre>

<i>xieperf</i> exercises the server functionality; it provides unit testing and
a reasonable measure of multi-element photoflo testing.

A draft standard of the XIElib specification is included in this release and is
open for Public Review.  The XIElib code matches the 5.0 protocol.

The JPEG compression and decompression code is based on the Independent JPEG
Group's (IJG) JPEG software, Release 4.  This software provides baseline
Huffman DCT encoding as defined by ISO/IEC DIS 10918-1, “Digital Compression
and Coding of Continuous-tone Still Images, Part 1: Requirements and
guidelines”, and was chosen as a basis for our implementation of JPEG
compression and decompression primarily because the IJG's design goals matched
ours for the implementation of the XIE SI: achieve portability and flexibility
without sacrificing performance.  Less than half of the files distributed by
the IJG have been incorporated into the XIE SI.  The IJG's software is made
available with restrictions; see
<b>xc/programs/Xserver/XIE/mixie/jpeg/README</b>.

### Inter-Client Communications Conventions Manual

Release 6 includes version 2.0 of the ICCCM.  This version contains a
large number of changes and clarifications in the areas of window
management, selections, session management, and resource sharing.

#### Window Management

The circumstances under which the window manager is required to send synthetic
ConfigureNotify events have been clarified to ensure that any ConfigureWindow
request issued by the client will result in a ConfigureNotify event, either from
the server or from the window manager.  We have also added advice about how a
client should inspect events so as to minimize the number of situations where it
is necessary to use the TranslateCoordinates request.

The window_gravity field of WM_NORMAL_HINTS has a new value, StaticGravity,
which specifies that the window manager should not shift the client window's
location when reparenting the window.

The base size in the WM_NORMAL_HINTS property is now to be included in the
aspect ratio calculation.

The WM_STATE property now has a formal definition (it was previously only
suggested).

#### Selections

We have clarified the CLIENT_WINDOW, LENGTH, and MULTIPLE targets.  We have also
added a number of new targets for Encapsulated PostScript and for the Apple
Macintosh PICT structured graphics format.  We have also defined a new selection
property type C_STRING, which is a string of non-zero bytes.  (This is in
contrast to the STRING type, which excludes many control characters.)

A selection requester can now pass parameters in with the request.

Another new facility is manager selections.  This use of the selection mechanism
is not to transfer data, but to allow clients known as <i>managers</i> to
provide services to other clients.  Version 2.0 also specifies that window
managers should hold a manager selection.  At present, the only service defined
for window managers is to report the ICCCM version number to which the window
manager complies.  Now that this facility is in place, additional services can
be added in the future.

#### Resource Sharing

A prominent new addition in version 2.0 is the ability of clients to take
control of colormap installation under certain circumstances.  Earlier versions
of the ICCCM specified that the window manager had exclusive control over
colormap installation.  This proves to be inconvenient for certain situations,
such as when a client has the server grabbed.  Version 2.0 allows clients to
install colormaps themselves after having informed the window manager.  Clients
must hold a pointer grab for the entire time they are doing their own colormap
installation.

Version 2.0 also clarifies a number of rules about how clients can exchange
resources.  These rules are important when a client places a resource ID into
a hints property or passes a resource ID through the selection mechanism.

#### Session Management

Some of the properties in section 5 of ICCCM 1.1 are now obsolete, and new
properties for session management have been defined.

### ICE (Inter-Client Exchange)

ICE provides a common framework to build protocols on.  It supplies
authentication, byte order negotiation, version negotiation, and error reporting
conventions.  It supports multiplexing multiple protocols over a single
transport connection.  ICElib provides a common interface to these mechanisms so
that protocol implementors need not reinvent them.

An <i>iceauth</i> program was written to manipulate an ICE authority file; it is
very similar to the <i>xauth</i> program.

### SM (Session Management)

The X Session Management Protocol (XSMP) provides a uniform mechanism for users
to save and restore their sessions using the services of a network-based session
manager.  It is built on ICE.  SMlib is the C interface to the protocol.  There
is also support for XSMP in Xt.

A simple session manager, <i>xsm</i> is included in
<b>xc/workInProgress/xsm</b>.

A new protocol, rstart, greatly simplifies the task of starting applications
on remote machines.  It is built upon already existing remote execution
protocols such as <i>rsh</i>.  The most important feature that it adds is the
ability to pass environment variables and authentication data to the
applications being started.

### Input Method Protocol

Some languages need complex pre-editing input methods, and such an input method
may be implemented separately from applications in a process called an Input
Method (IM) Server.  The IM Server handles the display of pre-edit text and the
user's input operation.  The Input Method (IM) Protocol standardizes the
communication between the IM Server and the IM library linked with the
application.

The IM Protocol is a completely new protocol, based on experience with R5's
sample implementations.  The following new features are added, beyond the
mechanisms in the R5 sample implementations:

 * The IM Server can support any of several transports for connection with
   the IM library.

 * Both the IM Server and clients can authenticate each other for security.

 * A client can connect to an IM Server without restarting even if
   it starts up before the IM Server.

 * A client can initiate string conversion to the IM Server for re-conversion
   of text.

 * A client can specify some keys as hot keys, which can be used to escape
   from the normal input method processing regardless of the input method state.

The R6 sample implementation for the internationalization support in Xlib has
a new pluggable framework, with the capability of loading and switching locale
object modules dynamically.  For backward compatibility, the R6 sample
implementation can support the R5 protocols by switching to IM modules
supporting those protocols.  In addition, the framework provides the following
new functions and mechanisms:
<dl>
<dt>X Locale database format:</dt>
<dd>An X Locale database format is defined, and the subset of a user's
   environment dependent on language is provided as a plain ASCII text file.
   You can customize the behavior of Xlib without changing Xlib itself.</dd>
<dt>ANSI C and non-ANSI C bindings</dt>
<dd>The common set of methods and structures are defined, which bind the X locale
   to the system locales within libc, and a framework for implementing this
   common set under non-ANSI C base system is provided.</dd>
<dt>Converters</dt>
<dd>The sample implementation has a mechanism to support various encodings by
   pluggable converters, and provides the following converters:
   <ul>
    <li>Light weight converter for C and ISO 8859</li>
    <li>Generic converter (relatively slow) for other encoding</li>
    <li>High performance converter for Shift-JIS and EUC</li>
    <li>Converter for UCS-2 defined in ISO/IEC 10646-1</li>
   </ul>
   You can add your converter using this mechanism for your specific performance
   requirement.</dd>
<dt>Locale modules</dt>
<dd>The library is implemented such that input methods and output methods are
   separated and are independent of each other.  Therefore, an output-only
   client does not link with the IM code, and an input-only client does not link
   with the OM code.  Locale modules can be loaded on demand if the platform
   supports dynamic loading.</dd>
<dt>Transport Layer</dt>
<dd>There are several kinds of transports for connection between the IM library
   and the IM Server.  The IM Protocol is independent of a specific transport
   layer protocol, and the sample implementation has a mechanism to permit an IM
   Server to define the transports which the IM Server is willing to use.  The
   sample implementation supports transport over the X protocol, TCP/IP and
   DECnet.</dd>
</dl>

There are IM Servers for Japanese and for Korean, internationalized clients
using IM services, and an IM Server developer's kit in contrib.  The IM Server
developer's kit hides the details of the IM Protocol and the transport layer
protocols, and hides the differences between the R5 and R6 protocols from the IM
Server developer, so that an IM developer has an easier task in developing new
IM Servers.

### X Logical Font Description

The X Logical Font Description has been enhanced to include general 2D linear
transformations, character set subsets, and support for polymorphic fonts.  See
<b>xc/doc/specs/XLFD/xlfd.tbl.ms</b> for details.

### SYNC extension

The Synchronization extension lets clients synchronize via the X server.
This eliminates the network delays and the differences in synchronization
primitives between operating systems.  The extension provides a general
Counter resource; clients can alter the value of a Counter, and can block
their execution until a Counter reaches a specific threshold.  Thus, for
example, two clients can share a Counter initialized to zero, one client can
draw some graphics and then increment the Counter, and the other client can
block until the Counter reaches a value of one and then draw some additional
graphics.

### BIG-REQUESTS extension

The standard X protocol only allows requests up to 2<super>18</super> bytes
long.  A new protocol extension, BIG-REQUESTS, has been added that allows a
client to extend the length field in protocol requests to be a 32-bit value.
This useful for PEX and other extensions that transmit complex information to
the server.

### XC-MISC extension

A new extension, XC-MISC, allows clients to get back ID ranges from the
server.  Xlib handles this automatically under the covers.  This is useful for
long-running applications that use many IDs over their lifetime.

### XTEST extension

The XTEST extension, which first shipped as a patch to Release 5, is included.

### Tree Reorganization

Many of the directories under <b>xc/</b> (renamed from <b>mit/</b>) have been
moved.  See the section <b>The XC Tree</b> for the new layout.  The
reorganization has simplified dependencies in the build process.  Once you get
used to the new layout, things will be easier to find.

Various filenames have been changed to minimize name conflicts on systems that
limit file names to eight characters, a period, and three more characters.
Conflicts remain for various header (.h) files.

### Configuration Files

The configuration files have changed quite a bit, we hope in a mostly compatible
fashion.  The main config files are now in <b>xc/config/cf</b>, imake sources
are in <b>xc/config/imake</b>, and makedepend sources are in
<b>xc/config/makedepend</b>.  The <i>lndir</i> program (for creating link trees)
is in <b>xc/config/util</b>; there is a <b>Makefile.ini</b> in that directory
that may be useful to get <i>lndir</i> built the first time (before you build
the rest of the tree).

The rules for building libraries have changed a lot; it is now much easier
to add a new library to the system.

The selection of <i>vendor</i><b>.cf</b> file has moved from <b>Imake.tmpl</b>
to a new <b>Imake.cf</b>.

The config variable that was called ServerOSDefines in R5 has been renamed
to ServerExtraDefines, and applies globally to all X server sources.  The
variable ServerOSDefines now applies just to the os directory of the server.

There are a number of new config variables dealing with C++, all of which have
“Cplusplus” in their names.

“#” should no longer be thought of as a valid comment character in Imakefiles;
use “XCOMM” instead.

There are new variables (e.g., HasPoll, HasBSD44Sockets, ThreadedX) and rules
(SpecialCObjectRule).  Read <b>xc/config/cf/README</b> for details.

The way libraries get built has changed: the unshared library .o's are now
placed in a subdirectory rather than the shared library .o's.

Multi-threaded programs can often just include <b>Threads.tmpl</b> in their
<b>Imakefile</b> to get the correct compile-time defines and libraries.

### Kerberos

There is a new authorization scheme for X clients, MIT-KERBEROS-5.  It
implements MIT's Kerberos Version 5 user-to-user authentication.  See
the <i>Xsecurity</i> manual page for details on how Kerberos works in X.
As with any other authentication protocol, <i>xdm</i> sets it up at
login time, and Xlib uses it to authenticate the client to the X server.

If you have Kerberos 5 on your system, set the HasKrb5 config variable
in <b>site.def</b> to YES to enable Kerberos support.

### X Transport Library (xtrans)

The X Transport Library is intended to combine all system and transport specific
code into a single place in the source tree.  This API should be used by all
libraries, clients and servers of the X Window System.  Note that this API is
<i>not</i> an X Consortium standard; it is merely in internal part of our
implementation.  Use of this API should allow the addition of new types of
transports and support for new platforms without making any changes to the
source except in the X Transport Interface code.

The following areas have been updated to use xtrans:

 * lib/X11 (including the Input Method code)
 * lib/ICE
 * lib/font/fc
 * lib/FS
 * XServer/os
 * xfs/os

The XDMCP code in xdm and the X server has not been modified to use xtrans.

No testing has been done for DECnet.

### Xlib

Xlib now supports multi-threaded access to a single display connection.  Xlib
functions lock the display structure, causing other threads calling Xlib
functions to be suspended until the first thread unlocks.  Threads inside Xlib
waiting to read to or write from the X server do not keep the display locked, so
for example a thread hanging on XNextEvent will not prevent other threads from
doing output to the server.

Multi-threaded Xlib runs on SunOS 5.3, DEC OSF/1 1.3, Mach 2.5 Vers 2.00.1, AIX
2.3, and Microsoft Windows NT 3.1.  Locking for Xcms and I18N support has not
been reviewed.  A version of ico that can be compiled to use threads is in
<b>contrib/programs/ico</b>.

The Display and GC structures have been made opaque to normal application
code; references to private fields will get compiler errors.  You can work
around some of these by compiling with -DXLIB_ILLEGAL_ACCESS, but better to
fix the offending code.

The Xlib implementation has been changed to support a form of asynchronous
replies, meaning that a request can be sent off to the server, and then other
requests can be generated without waiting for the first reply to come back.
This is used to advantage in two new functions, XInternAtoms and XGetAtomNames,
which reduce what would otherwise require multiple round trips to the server
down to a single round trip.  It is also used in some existing functions, such
as XGetWindowAttributes, to reduce two round trips to just one.

Lots of Xlib source files were renamed to fit better on systems with short
filenames.  The “X” prefix was dropped from most file names, and “CIE” and
“TekHVC” prefixes were dropped.

Support for using poll() rather than select() is implemented, selected by the
HasPoll config option.

The BIG-REQUESTS extension is supported.

The following Xlib functions are new in Release 6:
<pre>
     XInternAtoms, XGetAtomNames
     XExtendedMaxRequestSize
     XInitImage
     XReadBitmapFileData
     IsPrivateKeypadKey
     XConvertCase
     XAddConnectionWatch, XRemoveConnectionWatch, XProcessInternalConnection
     XInternalConnectionNumbers
     XInitThreads, XLockDisplay, XUnlockDisplay

     XOpenOM, XCloseOM
     XSetOMValues, XGetOMValues
     XDisplayOfOM, XLocaleOfOM
     XCreateOC, XDestroyOC
     XOMOfOC
     XSetOCValues, XGetOCValues
     XDirectionalDependentDrawing, XContextualDrawing
     XRegisterIMInstantiateCallback, XUnregisterIMInstantiateCallback
     XSetIMValues

     XAllocIDs
     XESetBeforeFlush
     _XAllocTemp, _XFreeTemp
</pre>

Support for MIT-KERBEROS-5 has been added.

### Internationalization

Internationalization (also known as I18N, there being 18 letters between the
<i>i</i> and <i>n</i>) of the X Window System, which was originally introduced
in Release 5, has been significantly improved in R6.  The R6 I18N architecture
follows that in R5, being based on the locale model used in ANSI C and POSIX,
with most of the I18N capability provided by Xlib.  R5 introduced a fundamental
framework for internationalized input and output.  It could enable basic
localization for left-to-right, non-context sensitive, 8-bit or multi-byte
codeset languages and cultural conventions.  However, it did not deal with all
possible languages and cultural conventions.  R6 also does not cover all
possible languages and cultural conventions, but R6 contains substantial new
Xlib interfaces to support I18N enhancements, in order to enable additional
language support and more practical localization.

The additional support is mainly in the area of text display.  In order to
support multi-byte encodings, the concept of a FontSet was introduced in R5.
In R6, Xlib enhances this concept to a more generalized notion of output
methods and output contexts.  Just as input methods and input contexts support
complex text input, output methods and output contexts support complex and
more intelligent text display, dealing not only with multiple fonts but also
with context dependencies.  The result is a general framework to enable
bi-directional text and context sensitive text display.

### Xt

Support has been added for participation in session management, with callbacks
to application functionality in response to messages from the session manager.

The entire library is now thread-safe, allowing one thread at a time to enter
the library and protecting global data as necessary from concurrent use.

Support is provided for registering event handlers for events generated by X
protocol extensions, and for dispatching those events to the appropriate widget.

A mechanism has also been added for dispatching events for non-widget drawables
(such as pixmaps used within a widget) to a widget.

Two new widget methods for instance allocation and deallocation allow widgets to
be treated as C++ objects in a C++ environment.

A new interface allows bundled changes to the managed set of children of a
Composite, reducing the visual disruption of multiple changes to geometry
layout.

Several new resources have been added to Shell widgets, making the library
compliant with the Release 6 ICCCM.  Parameterized targets of selections (new in
Release 6) and the MULTIPLE target are supported with new APIs.

Safe handling of POSIX signals and other asynchronous notifications is now
provided.

A hook has been added to give notification of blocking in the event manager.

The client will be able to register callbacks on a per-display basis for
notification of a large variety of operations in the X Toolkit.  This feature is
useful to external agents such as screen readers.

New String resource converters: XtStringToGravity and XtCvtStringToRestartStyle.

The file search path syntax has a new %D substitution that inserts the default
search path, making it easy to prepend and append to the default search path.

The Xt implementation allows a configuration choice of poll or select for I/O
multiplexing, selectable at compile time by the HasPoll config option.

The Release 6 Xt implementation requires Release 6 Xlib.  Specifically, it uses
the following new Xlib features: XInternAtoms instead of multiple XInternAtom
calls where possible, input method support (Xlib internal connections), and
tests for the XVisibleHint in the flags of XWMHints.

When linking with Xt, you now need to also link with SMlib and ICElib.  This
is automatic if you use the XTOOLLIB make variable or XawClientLibs <i>imake</i>
variable in your <b>Imakefiles</b>.

This implementation no longer allows NULL to be passed as the value in the
name/value pair in a request to XtGetValues.  The default behavior is to print
the error message “NULL ArgVal In XtGetValues” and exit.  To restore the R5
behavior, set the config variable <b>GetValuesBC</b> in <b>site.def</b>.  The
old behavior was never part of the Xt specification, but some applications
erroneously rely on it.

Motif 1.2 defines the types XtTypedArg and XtTypedArgList in VaSimpleP.h.  These
types are now defined in IntrinsicP.h.  To work around the conflict, in Motif
VaSimple.c, if IntrinsicP.h is not already included before VaSimpleP.h, do so.
In VaSimpleP.h, fence off the type declarations with #if (XT_REVISION < 6)
and #endif.

See Chapter 13 of the Xt specification for more details.

### Xaw

Some minor bugs have been fixed.  Please note that the Athena Widgets have
been and continue to be low on our priority list; therefore many bugs remain
and many requests for enhancements have not been implemented.

Text and Panner widget translations have been augmented to include keypad cursor
keysyms in addition to the normal cursor keysyms.

The Clock, Logo, and Mailbox widgets have moved to their respective
applications.

Internationalization support is now included.  Xaw uses native widechar support
when available, otherwise it uses the Xlib widechar routines.  Per system
specifics are set in XawI18n.h.

The shared library major version number on SunOS 4 has been incremented because
of these changes.

#### AsciiText

The name AsciiText is now a misnomer, but has been retained for backward
compatibility.  A new resource, XtNinternational, has been added.  If the
value of the XtNinternational resource is False (the default) AsciiSrc
and AsciiSink source and sink widgets are created, and the widget behaves
as it did for R5.  If the value is True, MultiSrc and MultiSink source and
sink widgets are created.  The MultiSrc widget will connect to an Input
Method Server if one is available, or if one isn't available, it will
use an Xlib internal pseudo input method that, at a minimum, does compose
processing.  Application programmers who wish to use this feature will need
to add a call to XtSetLanguageProc to their programs.

The symbolic constant FMT8BIT has been changed to XawFmt8Bit to be consistent
with the new symbolic constant XawFmtWide.  FMT8BIT remains for backwards
compatibility, however its use is discouraged as it will eventually be removed
from the implementation.  See the Xaw manual for details.

#### Command, Label, List, MenuButton, Repeater, SmeBSB, and Toggle

Two new resources have been added, XtNinternational and XtNfontSet.  If
XtNinternational is set to True the widget displays its text using the
specified fontset.  See the Xaw manual for details.

### PEX

In discussing PEX it is important to understand the nature of 3D graphics
and the purpose of the existence of the PEX SI.  The type of graphics for
which PEX provides support, while capable of being done in software, is
most commonly found in high performance hardware.  Creation and maintenance
of software rendering code is costly and resource consumptive.  The original
Sample Implementation for the PEX Protocol 5.0 was primarily intended for
consumption by vendors of the X Consortium who intended to provide PEX
products for sale.  This implementation was intended to be fairly complete
however it was understood that vendors who intended to commercialize it
would dispose of portions of it, often fairly substantial ones.  It was
therefore understood that functionality most likely to be disposed of by
them might be neglected in the development of a Sample Implementation.
As PEX is now a fairly mature standard distributed by most if not all major
vendors, and the standard itself has evolved from the 5.0 protocol level
to the 5.1 protocol level, the X Consortium and its supporting vendors have
recognized a need to focus on certain portions of the PEX technology while
deemphasizing others.

This release incorporates PEX functionality based upon the PEX 5.1 level
protocol.  The PEX Sample Implementation (SI) is composed of several parts.  The
major components are the extension to the X Server, which implements the PEX 5.1
protocol, and the client side API, which provides a mechanism by which clients
can generate PEX protocol.

The API now provided with the PEX-SI is called PEXlib.  This is a change from R5
which shipped an API based upon the ISO IS PHIGS and PHIGS PLUS Bindings.  That
API has been moved to contrib in favor of the PEXlib API based upon the PEXlib
5.1 binding, which itself is an X Consortium standard.  The PEXlib binding is a
lower-level interface than the previous PHIGS binding was and maps more closely
to the PEX protocol itself.  It supports immediate mode rendering functionality
as well as the previous PHIGS workstation modes and is therefore suited to a
wider range of applications.  It is also suited for the development of higher
level APIs.  There are in fact commercial implementations of the PHIGS API which
utilize the PEXlib API.

The PHIGS API based verification tool called InsPEX is moved to contrib.
A prototype of a possible new tool called suspex is in the directory
<b>contrib/test/suspex</b>.  Suspex is PEXlib based.

Demo programs are no longer supported and have moved to contrib.

#### PEX Standards and Functionality

This release conforms to the PEX Protocol Specification 5.1 though it
does not implement all the functionality specified therein.

The release comes with 2 fonts, Roman and Roman_M (see the <i>User's
Guide</i> for more details).

As discussed briefly above certain functionality is not implemented in this
Sample Implementation.  Most notably Hidden Line, Hidden Surface Removal is
not implemented.  This is a result of both architectural decisions and the
fact that it surely would have been replaced by vendors with proprietary
code.  A contributed implementation which supports some of the HLHSR
functionality utilizing a Z buffer based technique is available for ftp
from ftp.x.org in the directory contrib/PEX_HLHSR.

This release does not support monochrome displays, though it does support 8
bit and 24 bit color.

Other functionality not complete in this release is:

 * Backface Attributes and Distinguish Flag
 * Font sharing between clients
 * Patterns, Hatches and associated attributes
 * Transparency
 * Depth Cueing for Markers

Double Buffering is available for the PHIGS Workstation subsets directly
through the workstation.  The buffer mode should be set on when creating the
workstation.  For immediate mode users double buffering is achieved via the
Multi Buffering Extension (aka MBX) found in the directory <b>xc/lib/Xext</b>.

PEX 5.1 protocol adds certain functionality to the Server extension, accessible
directly via the PEXlib API.  This functionality includes Picking via the
Immediate Mode Renderer (Render Elements and Accumulate State commands in
Chapter 6, all of Chapter 7); new Escape requests to allow vendors to support
optional functionality; a Match Rendering Targets request to return information
about visuals, depth and drawables the server can support; a noop Output
command; Hierarchical HLHSR control (i.e., during traversals); and renderer
clearing controls are the most important features.

### Header Files

Two new macros are defined in <b>Xos.h</b>: X_GETTIMEOFDAY and strerror.
X_GETTIMEOFDAY is like gettimeofday() but takes one argument on all systems.
strerror is defined only on systems that don't already have it.

A new header file <b>Xthreads.h</b> provides a platform-independent interface to
threads functions on various systems.  Include it instead of the system threads
header file.  Use the macros defined in it instead of the system threads
functions.


### Fonts

There are three new Chinese bdf fonts in <b>xc/fonts/bdf/misc</b>
(<b>gb16fs.bdf</b>, <b>gb16st.bdf</b>, <b>gb24st.bdf</b>).

Bitmap Charter fonts that are identical to the output generated from the outline
font have been moved to <b>xc/fonts/bdf/unnec_</b>{<b>75</b>,<b>100</b>}<b>dpi</b>.

The Type 1 fonts contributed by Bitstream, IBM, and Adobe that shipped in
contrib in Release 5 have been moved into the core.

Some of the <b>misc</b> fonts, mostly in the <i>Clean</i> family, have only the
ASCII characters, but were incorrectly labeled “ISO8859-1”.  These fonts have
been renamed to be “ISO646.1991-IRV”.  Aliases have been provided for the
Release 5 names.

The <b>9x15</b> font has new shapes for some characters.  The <b>6x10</b> font
has the entire ISO 8859-1 character set.

### Font library

The Type1 rasterizer that shipped in contrib in Release 5 is now part of the
core.

There is an option to have the X server request glyphs only as it needs them.
The X server then caches the glyphs for future use.

Aliases in a <b>fonts.alias</b> file can allow one scalable alias name to match
all instances of another font.  The “!” character introduces a comment line in
<b>fonts.alias</b> files.

A sample font authorization protocol, “hp-hostname-1” has been added.  It is
based on host names and is non-authenticating.  The client requesting a font
from a font server provides (or passes through from its client) the host name of
the ultimate client of the font.  There is no check that this host name is
accurate, as this is a sample protocol only.

The Speedo rasterizer can now read fonts with retail encryption.  This means
that fonts bought over-the-counter at a computer store can be used by the font
server and X server.

Many, many bugs have been fixed.

### Font server

The font server has been renamed from <i>fs</i> to <i>xfs</i> to avoid confusion
with an AFS program.  The default port has changed from 7000 (used by AFS) to
7100 and has been registered with the Internet Assigned Numbers Authority.

The font server now implements a new major protocol version, version 2.  This
change was made only to correct errors in the implementation of version 1.
Version 1 is still accepted by <i>xfs</i>.

You can now connect to <i>xfs</i> using the <b>local/</b> transport.

Many, many bugs have been fixed.

### X server

The server sources have moved to <b>xc/programs/Xserver</b>.  Server-side
extension code exists as subdirectories.  The <b>ddx</b> directory is gone;
<b>mi</b>, <b>cfb</b>, and <b>mfb</b> are at the top level, and a <b>hw</b>
(hardware) subdirectory now exists for holding vendor-specific ddx code.  Note:
the absence of a ddx directory does not imply that the conceptual split between
dix and ddx is gone.

Function prototypes have been added to header files in
<b>xc/programs/Xserver/include</b>, <b>cfb</b>, <b>mfb</b>, <b>mi</b>, and
<b>os</b>.

Support for pixmap privates has been added.  It is turned off by default, but
can be activated by putting \-DPIXPRIV in the ServerExtraDefines parameter in
your <i>vendor</i><b>.cf</b> file.  See the porting layer document for details.

New screen functions, called primarily by code in window.c, have been added to
make life easier for vendors with multi-layered framebuffers.  Several
functions and some pieces of functions have moved from window.c to miwindow.c.
See the porting layer document for details.  Also, the contents of union
_Validate (validate.h) are now device dependent; mivalidate.h contains a
sample definition.

An implementation of the SYNC extension is in <b>xc/programs/Xserver/Xext/sync.c</b>.
As part of this work, client priorities have also been implemented; see the tail
end of WaitForSomething() in WaitFor.c.  The priority scheme is <i>strict</i> in
that the client(s) with the highest priority always runs.  <i>twm</i> has been
modified to provide simple facilities for setting client priorities.

The server can now fetch font glyphs on demand instead of loading them
all at once.  See <b>xc/programs/Xserver/dix/dixfonts.c</b>,
<b>xc/lib/font/fc/fserve.c</b>, and <b>xc/lib/font/fc/fsconvert.c</b>.  A new
X server command line option, \fB\-deferglyphs\fP, controls which types of
fonts (8 vs. 16 bit) to demand load; see the X manual page for details.

The os layer now uses sigaction on POSIX systems; a new function OsSignal was
added for convenience, which you should use in your ddx code.

A new timer interface has been added to the os layer; see the functions in
os/WaitFor.c.  This interface is used by XKB, but we haven't tried to use it
anywhere else (such as Xext/sleepuntil.c) yet.

Redundant code for GC funcs was moved from cfbgc.c and mfbgc.c to migc.c.
This file also contains a few utility functions such as miComputeCompositeClip,
which replaces the chunk of code that used to appear near the top of most
versions of ValidateGC.

The cfb code can now be compiled multiple times to provide support for multiple
depths in the same server, e.g., 8, 12, and 24.  See <b>Imakefile</b> and
<b>cfb/cfbmskbits.h</b> under the <b>xc/programs/Xserver/</b> directory for
starters.

The cfb and mfb code have been modified to perform 64 bit reads and writes of
the framebuffer on the Alpha AXP.  These modifications should be usable on
other 64 bit architectures as well, though we have not tested it on any
others.  There are a few hacks in dix, notably ProcPutImage and ProcGetImage,
to work around the fact that the protocol doesn't allow you to specify 64 bit
padding.  Note that the server will still not run on a machine such as a Cray
that does not have a 32 bit data type.

For performance, all region operations are now invoked via macros which by
default make direct calls to the appropriate mi functions.  You can
conditionally compile them to continue calling through the screen structure.
The following change was made throughout the server:
    “(*pScreen->RegionOp)(...)” changes to “REGION_OP(pScreen, ...)”

Some of the trivial region ops have been inlined in the macros.  For
compatibility, the region function pointers remain in the screen structure
even if the server is compiled to make direct calls to mi.  See
include/regionstr.h.

A generic callback manager is included and can be used to add
notification-style hooks anywhere in the server.  See dixutils.c.  The
callback manager is now being used to provide notification of when the
server is grabbed/ungrabbed, when a client's state changes, and when
an event is sent to a client.  The latter two are used by the RECORD
extension.

A new option has been added, <b>-config</b> <i>filename</i>.  This lets
you put server options in a file.  See <b>os/utils.c</b>.

Xtrans has been installed into the os layer.  See os/connection.c, io.c, and
transport.c.  As a result, the server now supports the many flavors of SVR4
local connections.

The client structure now has privates like windows, pixmaps, and GCs.  See
include/dixstruct.h, dix/privates.c, and dispatch.c.

Thin line pixelization is now consistent across cfb, mfb, and mi.  It
is also reversible, meaning the same pixels are touched when drawing
from point A to point B as are touched when drawing from point B to
point A.  A new header file, miline.h, consolidates some miscellaneous
line drawing utilities that had previously been duplicated in a number
of places.

#### Xnest

A new server, Xnest, uses Xlib to implement ddx rendering.  See
xc/programs/Xserver/hw/xnest.  Xnest lets you run an X server in a window on
another X server.  Uses include testing dix and extensions, debugging client
protocol errors, debugging grabs, and testing interactive programs in a
hardware-starved environment.

#### Xvfb

Another new server, Xvfb, uses cfb or mfb code to render into a
framebuffer that is allocated in virtual memory.  See
<b>xc/programs/Xserver/hw/vfb</b>.  The framebuffer can be allocated in
normal memory, shared memory, or as a memory mapped file.  Xvfb's
screen is normally not visible; however, when allocated as a memory
mapped file, <i>xwd</i> can display the screen by specifying the framebuffer
file as its input.

#### ddx

<dl>
<dt>Sun ddx</dt>
<dd>Expanded device probe table finds multiple frame buffers of the same type.
   Expanded keymap tables provide support for European and Asian keyboards.
   Added per-key autorepeat support.  Considerable cleanup and duplicate code
   eliminated.  Deletion of SunView support.  GX source code now included.</dd>
<dt>HP ddx</dt>
<dd>cfb-based sources included as <b>xc/programs/Xserver/hw/hp</b>.</dd>
<dt>svga ddx</dt>
<dd>new svga ddx for SVR4 included as <b>xc/programs/Xserver/hw/svga</b>.</dd>
<dt>xfree86 ddx</dt>
<dd>ddxen from XFree86, Inc. included as <b>xc/programs/Xserver/hw/xfree86</b>.</dd>
<dt>Amoeba ddx</dt>
<dd>ddx for Sun server on the Amoeba operating system included as
   <b>xc/programs/Xserver/hw/sunAmoeba</b>.  The server will require
   additional patches for this to be usable.</dd>
</dl>

### New Programs

<b>xc/config/util/mkshadow/</b>, a replacement for <i>lndir</i>.

### Old Software

We have dropped support for the following libraries and programs
and have moved them to <b>contrib</b>:
CLX library,
PHIGS library,
<i>MacFS</i>,
<i>auto_box</i>,
<i>beach_ball</i>,
<i>gpc</i>,
<i>ico</i>,
<i>listres</i>,
<i>maze</i>,
<i>puzzle</i>,
<i>showfont</i>,
<i>viewres</i>,
<i>xbiff</i>,
<i>xcalc</i>,
<i>xditview</i>,
<i>xedit</i>,
<i>xev</i>,
<i>xeyes</i>,
<i>xfontsel</i>,
<i>xgas</i>,
<i>xgc</i>,
<i>xload</i>,
<i>xman</i>, and
<i>xpr</i>.

### xhost

Two new families have been registered: LocalHost, for connections over a
non-network transport, and Krb5Principal, for Kerberos V5 principals.

To distinguish between different host families, a new xhost syntax
“family:name” has been introduced.  Names are as before; families are
as follows:
<pre>
inet:   Internet host
dnet:   DECnet host
nis:    Secure RPC network name
krb:    Kerberos V5 principal
local:  contains only one name, “\^”
</pre>
The old-style syntax for names is still supported when the name does not
contain a colon.

### xrdb

Many new symbols are defined to tell you what extensions and visual
classes are available.

### twm

An interface for setting client priorities with the Sync extension has been
added.

Many bugs have not been fixed yet.

### xdm

There is a new resource, <b>choiceTimeout</b>, that controls how long
to wait for a display to respond after the user has selected a host
from the chooser.

Support has been added for a modular, dynamically-loaded greeter
library.  This feature allows different dynamic libraries to by loaded
by <i>xdm</i> at run-time to provide different login window interfaces
without access to the <i>xdm</i> sources.  It works on DEC OSF/1 and SVR4.
The name of the greeter library is controlled by another new resource,
<b>greeterLib</b>.

When you log in via <i>xdm</i>, <i>xdm</i> will use your password to
obtain the initial Kerberos tickets and store them in a local
credentials cache file.  The credentials cache is
destroyed when the session ends.

### xterm

Now supports a few escape sequences from HP terminals, such as memory
locking.  See <b>xc/doc/specs/xterm/ctlseqs.ms</b> for details.

The <b>termcap</b> and <b>terminfo</b> files have been updated.

<b>ctlseqs.ms</b> has moved out of the xterm source directory into
<b>xc/doc/specs/xterm</b>.

The logging mis-feature of xterm is removed.  This change first appeared as
a public patch to Release 5.

Many bugs have not been fixed yet.

### xset

The screen saver control option has two new sub-options to immediately activate
or deactivate the screen saver: <b>xset s activate</b> and <b>xset s reset</b>.

### X Test Suite

The X Test Suite, shipped separately from R5, is now part of the core
distribution in R6.

The code has been fixed to work on Alpha AXP.  The Xi tests contributed by HP
and XIM tests contributed by Sun are integrated.

### Work in Progress

Everything under <b>xc/workInProgress</b> represents a work in progress
of the X Consortium.

Fresco, Low Bandwidth X (LBX), the Record extension, and the X Keyboard
extension (Xkb, which logically belongs here but was too tightly coupled into
Xlib and the server to extract) are neither standards nor draft standards, are
known to need design and/or implementation work, are still evolving, and will
not be compatible with any final standard should such a standard eventually be
agreed upon.  We are making them available in early form in order to gather
broader experimentation and feedback from those willing to invest the time and
energy to help us produce better standards.

Any use of these interfaces in commercial products runs the risk of later source
and binary incompatibilities.

#### Fresco

R6 includes the first sample implementation of Fresco, a user interface system
specified using CORBA IDL and implemented in C++.  Fresco is not yet a
Consortium standard or draft standard, but is being distributed as a work in
progress to demonstrate our current directions and to gather feedback on
requirements for a Fresco standard.

The Fresco Sample Implementation has been integrated into the X11R6 build
process, and will be built automatically if you have a C++ compiler available.
Documentation on Fresco can be found in <b>xc/doc/specs/Fresco</b>.  The Fresco
and Xtf libraries are found in <b>xc/workInProgress/Fresco</b> and
<b>xc/workInProgress/Xtf</b>, respectively.  There are some simple Fresco
example programs in <b>contrib/examples/Fresco</b>, and a number of related
programs in <b>contrib/programs</b>, including:
<dl>
<dt>ixx</dt>
<dd>An IDL to C++ translator</dd>
<dt>i2mif</dt>
<dd>A program to generate FrameMaker MIF documents from comments in an IDL
specification</dd>
<dt>fdraw</dt>
<dd>A simple Fresco drawing editor</dd>
<dt>dish</dt>
<dd>A TCL interpreter with hooks to Fresco</dd>
</dl>

Working Imakefiles are provided for all of the utilities and examples.

A demo program (dish) is included that shows how a scripting language (Tcl)
can rather easily be bound to Fresco through the CORBA dynamic invocation
mechanism.  A copy of Tcl is included in <b>contrib/lib/tcl</b>.

To build Fresco you must define HasCplusplus in <b>site.def</b>; in addition,
you may have to set CplusplusCmd and/or CplusplusDependIncludes to invoke the
appropriate C++ compiler and find the required header files during make depend.
Finally, you should check the <i>vendor</i><b>.cf</b> to see if there are any
other configuration variables you should set to provide information about your
C++ compiler.

Fresco requires a C++ compiler that implements version 3 of the C++ language
(as approximately defined by USL cfront version 3).  While Fresco does
not currently use templates or exceptions, it does make extensive use
of nested types, which were inadequately supported in earlier versions of
the language.

Fresco has been built with the following platforms and C++ compilers:
<pre>
SPARCstation    SunOS 4.1.3     CenterLine C++
SPARCstation    Solaris 2.3     CenterLine C++ (requires v2.0.6)
SPARCstation    Solaris 2.3     SPARCCompiler C++ v4.0
HP 9000/700     HPUX 9.0.1      CenterLine C++
SGI Indy        IRIX 5.2        SGI C++
IBM RS/6000     AIX 3.2.5       IBM xlC
Sony NEWS       NEWSOS 6.0      Sony C++
</pre>

Fresco has also been compiled on the DEC Alpha under OSF/1 version 2.0 using
a beta test version of DEC C++ 1.3.  Fresco cannot be built with the Gnu C++
compiler (version 2.5.8 or earlier) due to bugs and limitations in g++.

Fresco does not yet build under Microsoft Windows/NT.

#### XKB (X Keyboard Extension)

Support for XKB is not compiled in to Xlib by default.  It is compiled in the
X server by default only on Sun and Omron Luna machines.

Turning on XKB in the X server usually requires changes to the vendor ddx
keyboard handling.  There is currently support only in the Sun and Omron ddx.

If you turn on <b>BuildXKBLib</b>, additional functions are added to Xlib.
Since the resulting library is non-standard, it is given a different name:
<b>libX11kb</b> instead of <b>libX11</b>.  All Makefiles produced by
<i>imake</i> will use \fB\-lX11kb\fP to link Xlib.

The library changes for XKB are known not to work on the Cray; many other
systems have been tested, including the Alpha AXP.

There are some XKB test programs in <b>contrib/test/Xkb</b>.

The XKB support in Xlib is still at an early stage of formal review and could
change.  We expect some additions in an eventual standard, but few changes to
the interfaces provided in this implementation.  A working draft of the protocol
is in <b>/xc/doc/specs/Xkb/</b>.

#### LBX (Low Bandwidth X)

The X Consortium is working to define a standard for running X applications over
serial lines, wide area networks, and other slow links.  This effort, called Low
Bandwidth X (LBX), aims to improve the startup time, performance, and
interactive feel of X applications run over low bandwidth transports.

LBX does this by interposing a <i>pseudo-server</i> (called the <i>proxy</i>)
between the X clients and the X server.  The proxy caches data flowing between
the server and the clients, merges the X protocol streams, and compresses the
data that is sent over the low bandwidth wire.  The X server at the other end
uncompresses the data and splits it back out into separate request streams.  The
target is to make many X applications transparently usable over 9600 bps modems.

A snapshot of the code for this effort is included in
<b>xc/workInProgress/lbx/</b> for people to examine and begin experimenting
with.  It contains the following features:

 * LZW compression of the binary data stream.  Since commercial use
   of LZW requires licensing patented technology, we are also looking
   for an unencumbered algorithm and implementation to provide as well.

 * Delta compression of X packets (representing packets as differences
   from previously sent packets).

 * Re-encoding of some graphics requests (points, lines, segments,
   rectangles, and arcs).

 * Motion event throttling (to keep from flooding the wire).

 * Caching of data in the proxy for large data objects that otherwise
   would be transmitted over the wire multiple times (e.g., properties,
   font metrics, keyboard mappings, connection startup data, etc.).

 * Short-circuiting of requests for constant data (e.g., atoms,
   colorname/rgb mappings, and read-only color cells).

However, the following items have yet to be implemented (which is why it
isn't a standard yet):

 * Re-encoding of a number of requests (e.g., QueryFont), events, etc.

 * Support for BIG-REQUESTS extension.

 * A non-networked serial protocol for environments which cannot
   support os-level networking over serial lines.

 * A full specification needs to be written describing the network
   protocol used between the proxy and the server.

The X Consortium is continuing to work on both the implementation of the
remaining items and the full specification.  The goal is to have all of the
pieces ready for public review later this year.  Since the specification for LBX
<i>will</i> change, we strongly recommend against anyone incorporating LBX into
a product based on this prototype.  But, they are encouraged to start looking at
the code, examining the concepts, and providing feedback on its design.

#### RECORD extension

RECORD is an X protocol extension that supports the recording of all core X
protocol and arbitrary X extension protocol.

A version of the extension is included in <b>xc/workInProgress/record</b>.
The implementation does not quite match the version 1.2 draft specification,
but the spec is going to change anyway; the version 1.3 draft is in
<b>xc/doc/specs/Xext/record.ms</b>.  The GetConfig request is not fully
implemented.  A test program is in <b>contrib/test/record</b>.

#### Simple Session Manager

A simple session manager has been developed to test the new Session Management
protocol.  At the moment, it does not exercise the complete XSMP protocol and
the user interface is rather simple.  While it does have enough functionality to
make it useful, it needs more work before we would want people to depend on it
or use it as a good example of how to implement the session protocol.

 * Handles accepting connections from clients

 * Handles graceful or unexpected termination of clients

 * Maintains database of all properties set by clients

 * User interface provides a way to issue checkpoint and shutdown messages to
   clients

 * Manages client interaction with the user

 * Can restart clients.  Clients running on remote machines are handled using
   the new <i>rstart</i> protocol.

 * Requires MIT-MAGIC-COOKIE-1 authentication from clients.

We have not yet written a proxy for connecting ICCCM 1.0 clients to the session
manager.

A sample client, <i>xsmclient</i>, has been written to demonstrate the session
support in Xt.

#### Multi-Threaded X Server

An attempt has been made to merge the multi-threaded server source with the
single-threaded source.  The result is in the <b>xc/workInProgress/MTXserver</b>
directory.  The sources here include only files that were changed from the
single-threaded server.  The multi-threaded server may not compile.
Unfortunately, the single-threaded server sources have continued to evolve since
this snapshot of the MTXserver was produced, so there is work to be done to get
the MTXserver sources back into a state where they can be compiled.

### ANSIfication

We've changed our sources to stop using the BSD function names index, rindex,
bcopy, bcmp; we now use strchr, strrchr, memcpy/memmove, and memcmp.  We still
use the name bzero (because there is no BSD equivalent for the general case of
memset) but it is translated to memset via a #define in <X11/Xfuncs.h>.  The
BSD function names are still supported in <X11/Xos.h> and <X11/Xfuncs.h>.

Most client-side uses of caddr_t should now be gone from our sources.

Explicit declarations of errno are now only used on non-ANSI systems.

The libraries use more standard POSIX *_t types.

### Miscellaneous

A new version of the <i>patch</i> program is in <b>xc/util/patch</b>; it
understands the unified diff format produced by GNU <i>diff</i>.

## Acknowledgements

Release 6 of X Version 11 is brought to you by X Consortium, Inc:
Bob Scheifler,
Janet O'Halloran,
Ralph Swick,
Matt Landau,
Donna Converse,
Stephen Gildea,
Jay Hersh,
Kaleb Keithley,
Ralph Mor,
Dave Wiggins,
and Gary Cutbill.

Many companies and individuals have cooperated and worked extremely hard to
make this release a reality, and our thanks go out to them.  You will find
many of them listed in the acknowledgements in the individual specifications.
Major implementation contributions come from Data General, Digital, Fujitsu, HP,
NCD, NCR, Omron, SGI, Sony, SunSoft, and XFree86.

Contributions were received from the follow people at various X Consortium
member companies.  Each X Window System release is the work of many, many
people, and this list is surely incomplete.

<dl>
<dt>Fresco</dt>
<dd>Mark Linton (Silicon Graphics); Chuck Price (SunSoft); Charles Brauer
   (Fujitsu); Steve Churchill (Fujitsu); Steve Tang (Stanford University);
   Douglas Pan (Fujitsu); Jean-Daniel Fekete (2001 S.A.)</dd>
<dt>Xlib</dt>
<dd>Courtney Loomis (Hewlett-Packard Company); Daniel Dardailler (Open Software
   Foundation)</dd>
<dt>Xlib internationalization</dt>
<dd>The manager of the internationalization project is Masahiko Narita (Fujitsu).
   The principal authors of Input Method Protocol document are Hideki Hiura
   (SunSoft) and Masahiko Narita (Fujitsu).  The principal authors of Xlib
   specification Chapter 13 are Hideki Hiura (SunSoft) and Shigeru Yamada
   (Fujitsu OSSI).  The principal producers of the sample implementation of the
   internationalization facilities are Jeffrey Bloomfield (Fujitsu OSSI),
   Takashi Fujiwara (Fujitsu), Hideki Hiura (SunSoft), Yoshio Horiuchi (IBM),
   Makoto Inada (Digital), Hiromu Inukai (Nihon SunSoft), Song JaeKyung (KAIST),
   Riki Kawaguchi (Fujitsu), Franky Ling (Digital), Hiroyuki Miyamoto (Digital),
   Hidetoshi Tajima (HP), Toshimitsu Terazono (Fujitsu), Makoto Wakamatsu
   (Sony), Masaki Wakao (IBM), Shigeru Yamada (Fujitsu OSSI) and Katsuhisa Yano
   (Toshiba).  The coordinators of the integration, testing, and release of this
   implementation are Nobuyuki Tanaka (Sony) and Makoto Wakamatsu (Sony).
   Others who have contributed on the architectural design or the testing of
   sample implementation are Hector Chan (Digital), Michael Kung (IBM), Joseph
   Kwok (Digital), Hiroyuki Machida (Sony), Nelson Ng (SunSoft), Frank Rojas
   (IBM), Yoshiyuki Segawa (Fujitsu OSSI), Makiko Shimamura (Fujitsu), Shoji
   Sugiyama (IBM), Lining Sun (SGI), Masaki Takeuchi (Sony), Jinsoo Yoon (KAIST)
   and Akiyasu Zen (HP).</dd>
<dt>Xt Intrinsics</dt>
<dd>Douglas Rand (Open Software Foundation), parameterized selections; Paul
   Asente (Adobe Systems Incorporated), extension event handling; Ajay Vohra
   (SunSoft), support for multithreading; Sam Chang (Novell), widget caching
   research; Larry Cable (SunSoft), object allocation and change managed set;
   Vania Joloboff (Open Software Foundation); Courtney Loomis (Hewlett-Packard
   Company); Daniel Dardailler (Open Software Foundation); and Ellis Cohen (Open
   Software Foundation).  The following people at Georgia Tech contributed the
   extensions for disability access: Keith Edwards, Susan Liebeskind, Beth
   Mynatt, and Tom Rodriguez.</dd>
<dt>Athena Widget Set</dt>
<dd>Frank Sheeran (Omron Data General)</dd>
<dt>X Logical Font Description</dt>
<dd>Paul Asente (Adobe Systems Incorporated); Nathan Meyers (Hewlett-Packard
   Company); Jim Graham (Sun); Perry A. Caro (Adobe Systems Incorporated)</dd>
<dt>Font Support Enhancments</dt>
<dd>Nathan Meyers (Hewlett-Packard Company), implementation of matrix
   enhancement, glyph caching, scalable aliases, sample authorization protocol</dd>
<dt>X Transport Library</dt>
<dd>Stuart R. Anderson (AT&amp;T Global Information Solutions)</dd>
<dt>X Keyboard Extension</dt>
<dd>Erik Fortune (Silicon Graphics), design and sample implementation; Jordan
   Brown (Quarterdeck Office Systems); Will Walker (Digital Equipment
   Corporation), AccessX portion; Mark Novak (Trace Center), AccessX portion</dd>
<dt>Low-Bandwidth X</dt>
<dd>Jim Fulton (Network Computing Devices); Dave Lemke (Network Computing
   Devices); Dale Tonogai (Network Computing Devices); Keith Packard (Network
   Computing Devices); Chris Kantarjiev (Xerox PARC)</dd>
<dt>X Image Extension</dt>
<dd>Bob Shelley (AGE Logic), protocol architect, lead implementation architect;
   Larry Hare (AGE Logic), server implementation; Dean Verheiden (AGE Logic),
   server implementation; Syd Logan (AGE Logic), xieperf; Gary Rogers (AGE
   Logic), JPEG code, XIElib documentation; Ben Fahy (AGE Logic), client and
   server implementation</DD>
<DT>ICCCM</DT>
<DD>Stuart Marks (SunSoft); Gabe Beged-Dov (Hewlett-Packard Company); Chan Benson
   (Hewlett-Packard Company); Jordan Brown (Quarterdeck Office Systems); Larry
   Cable (SunSoft); Ellis Cohen (Open Software Foundation); Brian Cripe
   (Hewlett-Packard Company); Susan Dahlberg (Silicon Graphics); Peter Daifuku
   (Silicon Graphics); Andrew deBlois (Open Software Foundation); Clive Feather
   (IXI); Christian Jacobi (Xerox PARC); Bill Janssen (Xerox PARC); Vania
   Joloboff (Open Software Foundation); Phil Karlton (Silicon Graphics); Mark
   Manasse (Digital Equipment Corporation); Todd Newman (Silicon Graphics);
   Keith Taylor (Hewlett-Packard Company); Jim VanGilder (Digital Equipment
   Corporation); Mike Wexler (Kubota Pacific); Michael Yee (Apple Computer)</DD>
<DT>ICE</DT>
<DD>Jordan Brown (Quarterdeck Office Systems); Vania Joloboff (Open Software
   Foundation); Stuart Marks (SunSoft)</DD>
<DT>XSMP</DT>
<DD>Mike Wexler (Kubota Pacific); Jordan Brown (Quarterdeck Office Systems);
   Ellis Cohen (Open Software Foundation); Vania Joloboff (Open Software
   Foundation); Stuart Marks (SunSoft)</dd>
<dt>SYNC Extension</dt>
<dd>Tim Glauert (Olivetti Research Limited); Dave Carver (Digital Equipment
   Corporation); Jim Gettys (Digital Equipment Corporation); Pete Snider
   (Digital Equipment Corporation)</DD>
<DT>RECORD</DT>
<DD>Martha Zimet (Network Computing Devices); Robert Chesler (Absol-puter);
   Kieron Drake (UniSoft); Marc Evans (Synergytics); Jim Fulton (Network
   Computing Devices); Ken Miller (Digital Equipment Corporation)</dd>
<dt>X Input Extension tests</dt>
<dd>George Sachs (Hewlett-Packard Company)</DD>
<DT>PEX</DT>
<DD>Ken Garnett (Shographics); Cheryl Huntington (Sun Microsystems); Karl Schultz
   (IBM); Jeff Stevenson (Hewlett-Packard Company); Paula Womack (Digital
   Equipment Corporation)</dd>
<dt>Multi-Buffering Extension</dt>
<dd>Eng-Shien Wu (IBM); John Marks (Hewlett-Packard Company); Ian Elliott
   (Hewlett-Packard Company)</dd>
<dt>X server</dt>
<dd>Milind Pansare (SunSoft), pixmap privates; Peter Daifuku (SGI), layered
   window support; David Lister (Adobe Systems Incorporated), callback manager;
   Ken Whaley (Kubota Pacific), thin line pixelization; Joel McCormack (Digital
   Equipment Corporation), 64-bit mfb and cfb; Rob Lembree (Digital Equipment
   Corporation), 64-bit mfb and cfb; Davor Matic (MIT), xnest ddx; Nathan Meyers
   (Hewlett-Packard Company), font support; Jordan Brown (Quarterdeck Office
   Systems), -config option; Michael Brenner (Apple Computer), macII ddx; Thomas
   Roell, svga ddx</dd>
<dt>Multi-Threaded X Server</dt>
<dd>John A. Smith (while at Data General), team leader; H. Chiba (Omron), ddx;
   Akeio Harada (Omron), ddx; Mike Haynes (Data General), dix; Hidenobu Kanaoka
   (Omron), ddx; Paul Layne (Data General), dix and ddx; Takayuki Miyake
   (Omron), ddx; Keith Packard (Network Computing Devices), design; Richard
   Potts (Data General), dix; Sid Manning (IBM), integration with core server;
   Rob Chesler (Absol-puter), integration with core server</dd>
<dt>xdm modular loadable greeter</dt>
<dd>Peter Derr (Digital Equipment Corporation)</dd>
<dt>x11perf</dt>
<dd>Joel McCormack (Digital Equipment Corporation); Graeme Gill (Labtam
   Australia); Mark Martin (CETIA)</dd>
<dt>config</dt>
<dd>Stuart R. Anderson (AT&amp;T Global Information Solutions); David Brooks (Open
   Software Foundation); Kendall Collett (Motorola); John Freeman (Cray); John
   Freitas (Digital Equipment Corporation); Patrick E. Kane (Motorola); Mark
   Kilgard (Silicon Graphics); Akira Kon (NEC); Masahiko Narita (Fujitsu); Paul
   Shearer (Sequent); Mark Snitily (SGCS)</dd>
<dt>XFree86 port</dt>
<dd>Stuart R. Anderson (AT&amp;T Global Information Solutions); Doug Anson; Gertjan
   Akkerman; Mike Bernson; David Dawes; Marc Evans; Pascal Haible; Matthieu
   Herrb; Dirk Hohndel; David Holland; Alan Hourihane; Jeffrey Hsu; Glenn Lai;
   Ted Lemon; Rich Murphey; Hans Nasten; Mark Snitily; Randy Terbush; Jon Tombs;
   Kees Verstoep; Paul Vixie; Mark Weaver; David Wexelblat; Philip Wheatley;
   Thomas Wolfram; Orest Zborowski</dd>
<dt>fonts</dt>
<dd>Under <b>xc/fonts/</b>, the <b>misc/</b> directory contains a family of
   fixed-width fonts from Dale Schumacher, several Kana fonts from Sony
   Corporation, two Hangul fonts from Daewoo Electronics, two Hebrew fonts from
   Joseph Friedman, two cursor fonts from Digital Equipment Corporation, and
   cursor and glyph fonts from Sun Microsystems.  The <b>Speedo</b> directory
   contains outline fonts contributed by Bitstream, Inc.  The <b>75dpi</b> and
   <b>100dpi</b> directories contain bitmap fonts contributed by Adobe Systems,
   Inc., Digital Equipment Corporation, Bitstream, Inc., Bigelow and Holmes, and
   Sun Microsystems, Inc.</dd>
</dl>

<div style="font-size: small; border-top: 1px solid black;">
<p>
Copyright &copy; <span itemprop="copyrightYear">1994</span>
<span itemprop="copyrightHolder"
 itemscope itemtype="http://www.schema.org/Organization">
<span itemprop="name">X Consortium</span>
</span>.
</p><p>
Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
“Software”, to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:
</p>
<p>
The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.
</p>
<p>
THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.
</p>
<p>
Except as contained in this notice, the name of the X Consortium shall
not be used in advertising or otherwise to promote the sale, use or
other dealings in this Software without prior written authorization
from the X Consortium.
</p>
<p>
<i>X Window System</i> is a trademark of X Consortium, Inc.
</p>
</div>
</div>