This page is going to talk about using MIPS emulators to test MIPS code on a non-MIPS computer.
A common MIPS Emulator is Spim which is fully cross platform. Another one is MIPS Assembler and Simulator, which has been successfuly deployed in used in a few high schools. QEMU is another common emulator environment for MIPS. Yet another Emulator is MARS a cross-platform Java MIPS IDE.
Open Virtual Platforms (OVP) http://www.OVPworld.org includes the freely available simulator OVPsim, a library of models of processors, peripherals and platforms, and APIs which enable users to develop their own models. The models in the library are open source, written in C, and include the MIPS 4K, 24K and 34K cores. These models are created and maintained by Imperas http://www.imperas.com and in partnership with MIPS Technologies have been tested and assigned the MIPS-Verified(tm) mark. Sample MIPS-based platforms include both bare metal environments and platforms for booting unmodified Linux binary images. These platforms/emulators are available as source or binaries and are fast, free, and easy to use. OVPsim is developed and maintained by Imperas and is very fast (100s of million instructions per second), and built to handle multicore architectures. To download the MIPS OVPsim simulators/emulators visit http://www.OVPworld.org/mips.