Wine is an implementation of the Windows API on top of X and Unix. It does not require Microsoft Windows, but can use native Windows DLLs if they are available. It provides both a development toolkit for porting Windows source code to Unix as well as a program loader, allowing many unmodified Windows programs to run on x86-based Unixes.
uBee512 emulates all of the Microbee Z80 series of microcomputers, including ROM, Floppy and Hard disk-based models. Up to 2MB of extended memory is supported. The optional on board sn76489 sound IC is also emulated. The display may use SDL or OpenGL video rendering. Z80 PIO emulation includes tape, speaker, RTC, serial to PC RS232, and mouse peripherals. Parallel port peripherals include BeeThoven (AY-3-8910), BeeTalker (SP0256-AL2), Compumuse (SN76489), DAC, printer, and joystick. Many disk image types and floppy disks are supported. A joystick may be optionally mapped to keys. A large number of options are available as well as a built in OSD console.
MDK (MIX Development Kit) provides tools for developing and executing, in a MIX virtual machine, MIXAL programs. The MIX is Donald Knuth's mythical computer, described in the first volume of The Art of Computer Programming, which is programmed using MIXAL, the MIX assembly language. MDK includes a MIXAL assembler (mixasm), a MIX virtual machine (mixvm) with a command line interface, a Guile-based virtual machine (mixguile), a GTK+ based GUI (gmixvm), and a mixvm-Emacs interface (mixvm.el). MDK utilities are extensible using Scheme.
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).