Microsoft - DOS/Windows OS Emulators

Name	Description
Bochs	Bochs is a PC emulator written by Kevin Lawton. It is capable of emulating enough of the components of a modern PC to run Windows 95 and Linux, as well as a few other PC operating systems. Bochs runs on Windows (95, 98, and NT), various flavors of UNIX, and BeOS.
DOSBox	DOSBox is a cross-platform emulator of a PC with DOS. It can run games written for DOS out of the local file system. The emulator is still under heavy development and it runs about 60% of the games it was designed for.
PCE	PCE is an IBM PC 5150 emulator. It emulates most of the hardware of an IBM PC 5150. The emulation is complete enough to boot DOS and run most DOS applications. PCE was written in ANSI-C and is licensed under the GNU General Public License, Version 2.
QTemu	QtEmu is an application that uses Qemu and KVM to run virtual machines. It is written in Qt4, and integrates well into the KDE desktop (though there is also a Linux version). It is meant to be a replacement for software such as VMware. It has the ability to run any operating system on your computer without the need for rebooting or even disturbing the operating system you already have installed. This allows you to easily test a new operating system or try a Live CD on your system without any danger to your computer.

Microsoft - DOS/Windows OS Emulators on Other Platforms

Windows/DOS (7)
BeOS (1)
Macintosh (6)
Consoles
-- Playstation 2 (1)
-- Nintendo DS (1)
-- Nintendo Wii (1)

Emulators For:
Windows/DOS
Unix/Linux
BeOS
Macintosh
Amiga
Consoles
Java
Palm OS
Pocket PC
Digital Cameras
Digital Phones
Calculators
QNX
Windows Mobile Smartphone
Microsoft Silverlight

Other Releases
Extenders
Frontends
ROMs (Public Domain)
Hacks
Cheats
Movies
Savestates
Music
Technical Documents
Translations

Utilities:
General
Auditing
Cheating
Development
Game Modification
Music Playback / Manipulation
Plugins