Why is DirectFB not more widely used in GNU/Linux? Are there crippling limitations to it that don't exist in X11?

Question

As far as I understand, DirectFB offers hardware acceleration for many kinds of graphics cards. Additionally, it\'s smaller, faster, and uses up less memory than X11. Why then,

Answer 1

X11 is far more portable than DirectFB. An X11 app can run on Linux, BSD, Solaris, AIX, HP-UX, MacOS X, Windows (via Cygwin or Exceed), and many more platforms. DirectFB is pretty much Linux-only.