The Machine Emulator, or tme, provides a general-purpose framework for computer emulation. The goal is to create a large library of modules, each emulating a specific computer chip, bus, board, etc. These modules offer standard interfaces that allow you to connect them together to create a whole machine emulation with a minimum of effort. It is possible to emulate a Sun 2/120 and a 3/150, both with NetBSD, and a SparcStation 2 with NetBSD or SunOS 4.1.4 (aka Solaris 1.1.2).
PEACE is a set of programs to run Win32 applications on a NetBSD/i386 box. PEACE is a "Win32-compatible package" rather than an "emulator" because instead of using an emulator executable, it extends the kernel and dynamic linker to understand Windows EXE and DLL file and provides a small implementation of the core Windows APIs.
spim is a self-contained software simulator for running R2000/R3000 assembly language programs. It reads and can immediately execute files containing assembly language code. spim also provides a debugger and simple set of operating system services. spim provides both a simple, textual interface and a fancier, graphical interface. The package includes complete source code and documentation.