openDLX is a DLX/MIPS ISA compatible pipeline simulator.
(Visit https://github.com/smetzlaff/openDLX for the latest development version or if You want to contribute.)
YALC is a virtual architecture designed for educational purpose. It models a DLX-like processor and its set of ASM instructions, a compiler from a high level language (C-like), and an IDE with syntax checking and highlighting.