Here you will find just a few simple FLTK programs intended to get the FLTK beginner off the ground with the first couple of programs. The hardest part about FLTK is getting the first program to build! The library itself is one of the simplest toolkits available today -- a working GUI in just a few lines of code. FLTK has a very nice GLUT layer to give GLUT programmers a bit more functionality than they have with GLUT and base OpenGL.
You can read a bit more about these examples on my home page.
Have fun!
-mitch