LFMat is an open source template fast C++ linear algebra library with storage compatible and asm specializations for 3DNow!, SSE, SSE2 and Altivec (e.g. for solvers) taking cache into account. There's a wide variety of structure and storage styles...
kasm is an assembler for the Saturn microprocessor, used in the HP48/HP49 calculators. It uses MASD syntax, which has only very small incompatibilities with the traditional syntax, supports a few constructs that make the assembly language be closer to a