FLTK 1.4 is based on the final release of FLTK 1.3.4.

Technically the branch was forked earlier, but all changes in FLTK 1.3.4
have also been (modified and) committed in branch-1.3-porting, which is
the base of branch-1.4.

FLTK 1.4 is intended to be mostly API compatible with FLTK 1.3.4 so
you don't need to change source code when you switch to FLTK 1.4.

However, the platform dependent code in FLTK 1.4 was rewritten to enable
better porting to new platforms. Basically all platform dependent code
has been isolated and implemented in virtual methods of "driver" classes.
See src/drivers and subdirectories.

More to come ...
