GTK+ is a highly usable, feature rich toolkit for creating graphical user interfaces which boasts cross platform compatibility and an easy to use API. GTK+ it is written in C, but has bindings to many other popular programming languages such as C++, Python and C# among others. GTK+ is licensed under the GNU LGPL 2.1 allowing development of both free and proprietary software with GTK+ without any license fees or royalties.

GTK+ has been involved in many projects and some big platforms.

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