Multiplicity (software)

Multiplicity is a computer program that allows the use of one keyboard and mouse to access two or more client computers from a host computer. It is distributed by Stardock as part of their ThinkDesk subscription, as well as being available separately.

Multiplicity is unlike remote desktop applications in that instead of opening windows to a client computer on a host computer’s desktop, the mouse pointer and keyboard focus shifts from one computer to another. It is closer in concept to a KVM switch, but while these have multiple cables to each computer, with Multiplicity the keyboard and mouse remain connected to the host computer and input is forwarded from the host to client machines via network connections, and each computer still needs its own display device. Switching is triggered by movement of the mouse to the appropriate side of the screen (or keyboard shortcuts, if desired), both from the desktop and in full-screen video modes.

Multiplicity comes in two versions, the standard Multiplicity and Multiplicity Pro. The standard version has all the above features, including the ability to copy and paste images and text between computers. The Pro version also allows the user to control up to six client computers as well as the ability to copy and paste files, folders, and other data between machines.

Supported platforms as of December 2005 are Windows XP (32-bit and x64, not IA-64), 2000, and Server 2003. A Mac OS X client is in development, due in part to the popularity of the Mac mini, however as of June 2009 there's been no further update on when the OS X client will be made available. A Linux client is reportedly planned, but has not yet been developed.

The standard TCP/IP port for Multiplicity is 30564.

Alternatives

• Synergy — A Free software option that allows users to use a single keyboard and mouse to control multiple computers over TCP/IP. It is multiplatform (Supporting Windows, linux, and others), and supports text copy and paste.

• MaxiVista — A commercial option that allows users to use a single keyboard and mouse to control multiple computers over TCP/IP. Additionally, MaxiVista allows to share the monitor of a computer with other computers to create a multi monitor setup with multiple computers.

• Any remote desktop software that runs on the X Window System, together with a suitable window manager, can achieve the same effect, though not as efficiently. This approach does not require the use of multiple displays, but Xinerama can be used if multiple displays are desired, if at least one of the machines is capable of connecting to multiple displays at the same time. However, the fact that this approach works by actually transporting the display output from the other machine(s) to the primary machine could make it too slow for demanding apps such as video/audio apps.

Further reading

• Multiplicity home page
• Multiplicity in action — blog post explaining usage
• Multiplicity user reviews at the Windows Marketplace