The D-Bus glib bindings are licensed to you under your choice of the Academic
Free License version 2.1, or the GNU General Public License version 2.  Both
licenses are included here.

In SPDX terms, this is:

SPDX-License-Identifier: AFL-2.1 OR GPL-2.0-or-later

Exceptions are noted in individual source files. In particular:

* dbus/dbus-bash-completion-helper.c is licensed more restrictively:
  it is under GPL-2.0-or-later, without the AFL-2.1 dual-license option.
  See that file for details.

* Some source files are more permissively licensed, with a
  LGPL-2.1-or-later or MIT option, or under the MIT license only.
  See individual source files for details.

Please see the files in LICENSES/ for full license text.