GCC Software Development Kit (GCCSDK) is a portable build environment for creating RISC OS executables to be run natively on RISC OS. The build environment is designed to be hosted on a Unix-like system, such as GNU/Linux, FreeBSD, Solaris, MacOS X or even Windows (under Cygwin). GCCSDK releases are tied-in with the corresponding GCC releases.

GCCSDK can be used to compile and develop GCC and UnixLib itself, or as the basis for a cross-compiling system. It includes a number of "porting scripts" which automate the process of building and configuring new ports, which would otherwise be difficult and error prone, and not possible when done natively under RISC OS.