Let's first check size... remember, we want to be "tiny" ;-)
tc@box:~/ext/Xorg$ ls -l /usr/lib/libfltk*.so.*
-rwxr-xr-x 1 tc staff 503192 Jul 9 2010 /usr/lib/libfltk.so.1.1
-rwxr-xr-x 1 root staff 915152 Jun 17 16:36 /usr/lib/libfltk.so.1.3
-rwxr-xr-x 1 tc staff 18388 Jul 9 2010 /usr/lib/libfltk_forms.so.1.1
-rwxr-xr-x 1 root staff 17332 Jun 17 16:36 /usr/lib/libfltk_forms.so.1.3
-rwxr-xr-x 1 root staff 85628 Jun 17 16:36 /usr/lib/libfltk_gl.so.1.3
-rwxr-xr-x 1 tc staff 50220 Jul 9 2010 /usr/lib/libfltk_images.so.1.1
-rwxr-xr-x 1 root staff 53936 Jun 17 16:36 /usr/lib/libfltk_images.so.1.3
gl could be disabled, fltk main library +410 K increase in size. That's quite much, if we don't have any features or real need for 1.3? And I doubt +410 K would be the end if we do down this road...