Quincy includes version 1.0 of FLTK along with online documentation for it. You can also find web and pdf versions of the FLTK manuals here:
There's quite a nice introduction to the basic building blocks and simple example programs in Chapter 2 and 3:
Some of the pictures don't seem to work on the web manual, so it may be a good idea to look at the PDF version.
In fact, there's a rather better walk-through of some simple programs in the FLTK 2.0 documentation in chapters 1-4, but before checking this out see the further notes below.
The problem with FLTK 2.0 is that the naming conventions and class interfaces were considerable altered (and version 2.0 never became stable). So although the documentation is nicer, the code is incompatible with FLTK 1.0, and FLTK 2.0 itself is not recommended. Nevertheless, much of the content of chapters 1-4 is useful, and the code examples are mostly equivalent to their FLTK 1.0 counterparts. To aid with reading these notes, I've back-ported the examples into FLTK 1.0 compliant code, which can be found below.
Example 2b: Buttons, Sliders, Output etc
Example 3: Using classes with FLTK
The longer text editor example is also provided in the FLTK 1.0 documentation if you'd like to see a bigger example of FLTK at work.
SJH 04 Nov 2011