FLTK (Fast Light Toolkit) pronounced fulltick is a cross-platform, free software, GUI library. It is written in the programming language C plus plus and is functional on Microsoft Windows, GNU/Linux, Mac OS X, Solaris_Operating_Environment, OS/2, and probably all Unix and Unix-like operating systems.

FLTK provides modern GUI functionality without bloat and supports 3D graphics via OpenGL® and its built-in GLUT emulation. It is currently maintained by a small group of developers across the world.

FLTK is designed to be small and modular enough to be statically linked - the hello, world program is only 97k when compiled on an x86 Linux system! FLTK also works fine as a shared library and is now being included on Linux distributions.

FLTK includes a UI builder called FLUID that can be used to create applications in minutes.

FLTK is distributed under the terms of the GNU Lesser General Public License, Version 2 with exceptions that allow for static linking. The execptions allow others to, either statically or dynamically, link its libraries into proprietary / Closed source programs. This means it is free software / open source software but it is not copyleft.

The Dillo web browser is currently being ported to FLTK.

= Branches =

FLTK 1.1.x is the current stable release branch. FLTK 2.0 is currently in development and available via Concurrent Versions System. Snapshots of 2.0.x are usualy providing backports to and released in pair with 1.1.x. Please see the software page for details.

FLTK 2.0 provides enhanced device, rendering, and style interfaces to support more platforms, printing, and application skins .

= External links =