MacWindows  
   Solutions for integrating Macintosh and Windows.
   http://www.macwindows.com/

Clone OS to Run Windows Apps  
   An Australian developer is building software that runs Windows NT applications but doesn't require software from Microsoft.
   http://www.wired.com/news/news/technology/story/20637.html

Flopper  
   A bootable-disk emulator - it reads a diskette image file (a file that contains all the sectors of a floppy disk) and boots it. This way, you can boot (and run) a bootable diskette off of your hard drive.
   http://www.oldskool.org/pc/flopper/

DOSEMU  
   An emulator of the Microsoft Disk Operating System (MS-DOS) for Linux/X11. Enables Linux to run many DOS programs - including some DPMI applications.
   http://www.dosemu.org/

Eliel Software Development  
   Software for developers and game players, featuring DodGE: the DOS Game Emulator for Windows.
   http://www.eliel.com

DOSBox  
   An open source DOS emulator for BeOS, Linux, MacOS X, and Windows. Primarily focuses on running DOS Games.
   http://dosbox.sourceforge.net/

WABI  
   WABI is a Windows 3.1 emulator for Linux.
   http://www.sco.com/support/docs/wabi/

Project David  
   A Windows compatibility middleware, which will enable all major Microsoft Windows applications to run on Linux. Describes the project.
   http://www.specopslabs.com/projdav-overview.htm