Nonpareil is a microcode-level simulator for HP calculators introduced between 1972 and 1982, including the HP-35, HP-45, HP-55, HP-25, HP-34C, HP-38C, HP-41CV, HP-11C, HP-12C, HP-15C, HP-16C, and other models. The necessary microcode is included, as is a microcode assembler. The GTK+ toolkit is used for the user interface.
OpenVPS is a set of software built on top of the Linux VServer aimed specifically at Web Hosting. It is not another set of kernel patches, but a set of scripts to create virtual servers, collect resource utilization information, and provide an interface to the customer as well as the administrator.
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.