cc65 is a complete cross development package for 65(C)02 systems, including a powerful macro assembler, a C compiler, linker, librarian and several other tools.It is based on a C compiler that was originally adapted for the Atari 8-bit computers by John R. Dunning. The original C compiler is a Small C descendant but has several extensions, and some of the limits of the original Small C compiler are gone.The toolkit has largely been expanded by Ullrich von Bassewitz and other contributors.