emuStudio is a free, cross-platform toy-computer emulation platform and framework. It targets the "academic" sphere to help students or enthusiasts gaining the "know-how" and experiment with how computers work.
Platform, because it supports full computer emulation "life-cycle". From writing and compiling programs for the emulated machine, to running and debugging. Examples of real computer emulators are MITS Altair8800, SSEM (a.k.a. "Baby"). Abstract computers include: RAM, RASP, and Brainfuck "emulator".
Framework, because it includes API and supporting back-end enabling developing new computer emulators. Good developer documentation is a matter of course. As in real computers, emuStudio allows reusing existing components resulting in different computer configurations.Follow @emuStudio
The following options might help you getting started with emuStudio.