GTK+ 3.2 with support for Wayland and HTML5
Version 3.2 of the GTK+ GUI library has been released. The new version brings several enhancements and improvements, including better CSS theming support, two new widgets (GtkLockButton and GtkOverlay) a refreshed file chooser and a new family of "GtkFontChooser" widgets. The most important changes, though, are still experimental: the support for HTML5 and the Wayland display server. Programs that use GTK+ 3.2 can run as web applications in HTML5-compliant browsers as this video shows:
GTK 3.2+ has experimental support for Wayland's slim display server. Mark Shuttleworth announced that he wanted Ubuntu to switch to Wayland in the medium to long term as a replacement for the X Window System which was originally developed in the 1980s. A Wayland backend for GTK+ would help that transition, not only because all GNOME applications use GTK+, but also because programs such as Gimp, Firefox and Chrome make use of it. The other much used toolkit in the Linux world, Qt, on which the KDE desktop is based, also has experimental support for Wayland.
GTK+ was originally the Gimp Tool Kit, used for image processing applications. The C-based cross-platform toolkit allows you to create applications for Linux, other Unix systems, Mac OS X and Windows, in languages from C to Python. Because of its use as the basis of the GNOME desktop, many Linux applications use GTK+. With version 3.0's release, GTK+ moved from being, as originally designed, a toolkit for the X Window System, and has expanded to make use of various backends.
GTK+ is licensed under the GNU LGPL and is part of the GNU Project.