FLTK is designed to be small and modular enough to be statically linked, but works fine as a shared library. FLTK also includes an excellent UI builder called FLUID that can be used to create applications in minutes. FLTK is provided under the terms of the GNU Library Public License, Version 2 with exceptions that allow for static linking.

Stability: GTK+ has been developed for over a decade to be able to deliver the enticing features and superb performance that it brings to your application development. GTK+ is supported by a large community of developers and has core maintainers from companies such as Red Hat, Novell, Lanedo, Codethink, Endless Mobile and Intel. Language Bindings: GTK+ is available in many other programming languages thanks to the language bindings available. This makes GTK+ quite an attractive toolkit for application development. Accommodating: GTK+ caters for a number features that today's developers are looking for in a toolkit including: ◦Native look and feel ◦Theme support ◦Thread safety ◦Object oriented approach ◦Internationalization ◦Localization ◦Accessibility ◦Bidirectional text support (LTR/RTL, Left To Right/Right To Left) ◦UTF8 support ◦Documentation Foundations: GTK+ is built on top of GLib. GLib provides the fundamental algorithmic language constructs commonly duplicated in applications. This library has features such as: (this list is not a comprehensive list) ◦Object and type system ◦Main loop ◦Dynamic loading of modules (i.e. plug-ins) ◦Thread support ◦Timer support ◦Memory allocator ◦Threaded Queues (synchronous and asynchronous) ◦Lists (singly linked, doubly linked, double ended) ◦Hash tables ◦Arrays ◦Trees (N-ary and binary balanced) ◦String utilities and charset handling ◦Lexical scanner and XML parser ◦Base64 (encoding & decoding) Mobile: The GMAE (GNOME Mobile & Embedded) initiative has advanced the use, development and commercialization of GNOME components as a mobile and embedded user experience platform. It has brought together industry leaders, expert consultants, key developers and the community and industry organizations they represent. As a direct result of this, GTK+ has features pertaining to mobile and embedded platform requirements.