In computing, Close To Metal ("CTM" in short, originally called Close-to-the-Metal) is the name of a beta version of a low-level programming interface developed by ATI, now the AMD Graphics Product Group, aimed at enabling GPGPU computing. CTM was short-lived, and the first production version of AMD's GPGPU technology is now called AMD Stream SDK, or the rather the current AMD APP SDK for Windows and Linux 32-bit and 64-bit. APP stands for "Accelerated Parallel Processing".