|Discontinued||5.5 / June 4, 2008|
Win4Lin was a proprietary software application for Linux which allowed users to run a copy of Windows 95, Windows 98, Windows Me, Windows 2000 or Windows XP applications on their Linux desktop. Citing changes in the desktop virtualization industry, the software's publisher, Virtual Bridges, has discontinued Win4Lin Pro.
Win4Lin operates by running Windows applications in a virtual machine, but does so while allowing access to the native Linux filesystem. Win4Lin came in three different versions, depending on the virtualization requirements of the user. Win4Lin 9x allowed the user to run a full copy of Windows 98 or Windows Me inside a virtual machine. Win4Lin Home allowed users to only emulate applications. Win4Lin Pro offered users the ability to install a fully virtualized Windows 2000 or Windows XP. Unlike CrossOver Office or Wine which are emulation-based, virtualization-based software such as VMware or Win4Lin require users to have a Windows license in order to run applications since they must install a full copy of Windows within the virtual machine. Unlike VMware, however, Win4Lin provides the virtual guest operating system with access to the native Linux filesystem, and allows the Linux host to access the guest's files even when the virtual machine is not running. In addition to the convenience this offers, Computerworld found that Win4Lin gained significant performance over VMware by using the native Linux filesystem.
When the Win4Lin application starts it displays a window on the Linux desktop which contains the Windows desktop environment. Users can then install or run applications as they normally would from within Windows. Win4Lin supports Linux printers, internet connections, and Windows networking, but does not support DirectX and by extension most Windows games.
Win4Lin was based on Merge software developed by engineers at Locus Computing Corporation, founded by Gerald J. Popek and others in 1982, which was later taken over by a company called Platinum Technology. Merge was originally developed to run DOS/Windows 3.1 under UNIX System V Release 2 on an AT&T 6300+ personal computer that contained an Intel 80286 processor. AT&T announced availability on October 9, 1985, referring to the bundled Merge software as SimulTask. Later Merge was enhanced to make use of the VM86 mode provided by the Intel 80386 processor; that version was offered with Microport SVR3 starting in 1987, and subsequently with SCO Unix.
The Merge technology was then bought by a company called DASCOM which was in turn bought by IBM. A company called TreLOS was then spun off that continued the development of the virtual machine software and created Win4Lin. TreLOS and LastFoot.com merged in 2000 to form NeTraverse, Inc.
In early 2005 the assets of NeTraverse were purchased to form Win4Lin Inc. which introduced Win4Lin Pro Desktop: this was based on a 'tuned' version of QEMU and KQEMU, and it hosted [Windows NT]-versions of Windows. In June 2006, Win4Lin released Win4VDI for Linux based on the same code base. Win4VDI for Linux served Microsoft Windows desktops to thin clients from a Linux server. Win4Lin Pro used "full" virtualization, whereas Win4Lin 9x was an example of paravirtualization. Many users reported that the 9x version ran windows software at near-native speed, even on quite low-powered machines, such as Pentium-IIs.
Virtual Bridges discontinued support for Win4Lin 9x in 2007. The Win4Lin Pro Desktop product ceased to be supported in March 2010.
 See also
- Hsiao, Aron (July 7, 2005). Sams teach yourself Red Hat Fedora 4 Linux: all in one. SAMS Publishing. p. 678. Retrieved Nov. 14, 2012.
- "Win4Lin Pro". Virtual Bridges. Archived from the original on Nov. 14, 2012. Retrieved Nov. 14, 2012.
- McCallister, Michael. Suse Linux 10: Unleashed. SAMS Publishing. pp. 191–192. Retrieved Nov. 14, 2012.
- Bushong, Charles (April 4, 2002). "Windows Emulators for Linux: VMware, Win4Lin Face Off". Computerworld. pp. 1–2. Retrieved Nov. 14, 2012.
- Petreley, Nicholas (Nov. 20, 2000). "Get Win4Lin and Windows users won't feel disenfranchised under Linux". InfoWorld. Retrieved Nov. 14, 2012.
- Petreley, Nicholas. "Am I the only one who doesn't know why to use VMware?". InfoWorld. p. 60. Retrieved 2012-11-14.