The Fast Light Tool Kit ("FLTK", pronounced "fulltick") is a cross-platform C++ GUI toolkit for UNIX
®/Linux®(X11), Microsoft®Windows®, and Apple®OS X®.
FLTK provides modern GUI functionality without the bloat and supports 3D graphics via OpenGL®and
its built-in GLUT emulation. It was originally developed by Mr. Bill Spitzak and is currently maintained
by a small group of developers across the world with a central repository in the US.