FLTK stands for fast light tool kit — it is a tool kit for building graphical user interfaces when programming in C++. Its features include

  • Open source. Its license is very unrestrictive. One may develop commercial software using FLTK without charge.
  • Cross platform. Programs may be compiled on Linux, Windows, Mac OSX, and others with little or no changes in source code.
  • Small executable programs. FLTK programs don’t have the special effects of some other tool kits (Unless you build them yourself).

The installation of FLTK provides many small example programs you can run to see the widgets in action. You can study these programs and use the code in your own software. The thing that has most endeared me to FLTK is the forum. I have had questions answered in minutes. For information, downloads, etc., go to

On this page, I intend to post examples I have developed that complement examples included in the distribution or posted elsewhere. I do this to help other learners as I was helped.