Minimal graphics lib for gcc on MacOS-X

Hi,
A member of my family studies C in his classroom under Windows, and they
use a Windows IDE.
On his MacOS-X Tiger machine, he uses gcc + Emacs, but lacks the
capability of opening a simple graphics window, and drawing lines.
Is there a *small* graphics lib he can include to get his project done
without diving in the arcane of XCode and Mac programming ?
A turtle graphics library should be the ideal so far.
Thanks for him (and probably many other students)...

JG