Once the program is installed, users can move the mouse "off" the side of their desktop on one computer, and the mouse pointer will appear on the desktop of another computer. Key presses will be delivered to whichever computer the mouse-pointer is located in. This makes it possible to control several machines as easily as if they were a single multi-monitor computer. The clipboard and even screensavers can be synchronized. The program is implemented as a server which defines which screen-edges lead to which machines, and one or more clients, which connect to the server to offer the use of their desktops. The keyboard and mouse are connected to the server machine. As of version 2.0 keystrokes, mouse movements and clipboard contents are sent via an encrypted SSL network connection. This previously required the purchase of the Pro edition in version 1. In July 2013 the Defuse Security Group reported the proprietary encryption used in Synergy 1.6 to be insecure and released an exploit which could be used to passively decrypt the commands sent to the Synergy 1.6 clients. This was solved by using SSL in 1.7. TCP/IP communications are used to send mouse, keyboard and clipboard events between computers in Synergy 1.
History
The first incarnation of Synergy was CosmoSynergy, created by Richard Lee and Adam Feder then at Cosmo Software, Inc., a subsidiary of SGI, at the end of 1996. They wrote it, and Chris Schoeneman contributed, to solve a problem: most of the engineers in Cosmo Software had both an Irix and a Windows box on their desks and switchboxes were expensive and annoying. CosmoSynergy was a great success but Cosmo Software declined to productize it and the company was later closed. Synergy is a from-scratch reimplementation of CosmoSynergy. It provides most of the features of the original and adds a few improvements. Synergy+ was created in 2009 as a maintenance fork for the purpose of fixing bugs inherited from the original version. The original version of Synergy had not been updated for a notable length of time. There was never official confirmation that the original Synergy project had been abandoned; however, there was public discussion providing speculation. In said discussion, Chris Schoeneman stated that instead of supporting a 1.3.x team, he intends on releasing version 2.0 of Synergy, and publicly announced on 27 Aug 2008 that he has been making progress on this version.
