OSDev.org

Hello!
I want to compile x86 elf binaries in OS X on PPC, so what do I have to make it work?
Do I have to download the sources for the x86 gcc and compile it with my PPC gcc, or is there any place on the Internet where I may download ready x86-elf-gcc?

You need a cross-compiler (from MacOSX-PPC to x86-ELF) so chances are you won't find one precompiled. IIRC our wonderful FAQ has a page about creating a cross-compiler at http://www.osdev.org/osfaq2/index.php/G ... s-Compiler
which might or might not be useful for you.