LLVM is available for many CPU architectures. Because there exists many different OSs you may encounter the situation that the CPU architecture of your OS is supported but not your OS itself. In order to natively run LLVM on such an OS you need to port LLVM. In this talk I share my experience in porting LLVM to AIX. LLVM supports Linux on PowerPC so aiming for AIX supports seems reasonable. I show the approach I took and which parts of LLVM must be modified, including how to tweak the MC layer to utilize an external assembler.