Synergy is a

software application Application software is any computer program that is intended for end-user use not computer operator, operating, system administration, administering or computer programming, programming the computer. An application (app, application program, sof ...

for sharing a keyboard and mouse between multiple computers. It is used in situations where several PCs are used together, with a monitor connected to each, but are to be controlled by one user. The user needs only one keyboard and mouse on the desk—similar to a

KVM switch A KVM switch (with KVM being an abbreviation for "keyboard, video, and mouse") is a hardware device that allows a user to control multiple computers from one or more sets of keyboards, video monitors, and mouse. Name Switches to connect ...

without the video. Partly open source and partly closed source, the open source components are released under the terms of the

GNU General Public License The GNU General Public Licenses (GNU GPL or simply GPL) are a series of widely used free software licenses, or ''copyleft'' licenses, that guarantee end users the freedom to run, study, share, or modify the software. The GPL was the first ...

, which is

free software Free software, libre software, libreware sometimes known as freedom-respecting software is computer software distributed open-source license, under terms that allow users to run the software for any purpose as well as to study, change, distribut ...

. The first version of Synergy was created on May 13, 2001, by Chris Schoeneman and worked with the

X Window System The X Window System (X11, or simply X) is a windowing system for bitmap displays, common on Unix-like operating systems. X originated as part of Project Athena at Massachusetts Institute of Technology (MIT) in 1984. The X protocol has been at ...

only. Synergy now supports

Windows Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...

macOS macOS, previously OS X and originally Mac OS X, is a Unix, Unix-based operating system developed and marketed by Apple Inc., Apple since 2001. It is the current operating system for Apple's Mac (computer), Mac computers. With ...

Linux Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...

, and other Unix-like operating systems.

Design

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 A clipboard is a thin, rigid writing board with a clip at the top for holding paper in place. A clipboard is typically used to support paper with one hand while writing on it with the other, especially when other writing surfaces are not avail ...

and even

screensaver A screensaver (or screen saver) is a computer program that blanks the display screen or fills it with moving images or patterns when the computer has been idle for a designated time. The original purpose of screensavers was to prevent phosphor s ...

s can be synchronized. The program is implemented as a

server Server may refer to: Computing *Server (computing), a computer program or a device that provides requested information for other programs or devices, called clients. Role * Waiting staff, those who work at a restaurant or a bar attending custome ...

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 (2017) 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 that 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 The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the suite are ...

communications ( default port 24800) 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 (née Silicon Graphics, Inc.), 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 (as of 6 June 2010, the latest release was 2 April 2006). 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 (the creator of Synergy) 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.

References

External links

* * - Official source code * - Formerly user-maintained fork of Synergy 1.9 (no maintenance since February 2022) * {{github, input-leap/input-leap - User-maintained fork of Synergy 1.9 Free software programmed in C++ Free system software Keyboard-sharing software Linux network-related software Remote desktop Remote desktop software for Linux Utilities for Linux Utilities for macOS Utilities for Windows Virtual Network Computing

Design

History

See also

References

External links