Synergy (software)
Encyclopedia
Synergy is a software application 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
without the video.
Released under the terms of the GNU General Public License
, Synergy is free software
.
The first version of Synergy (created on May 13, 2001 by Chris Schoeneman, also known as "crs") worked with the X Window System
only, but more recent versions of Synergy support Windows, Mac OS X
, Linux
and other Unix dialects.
A fork of Synergy named Synergy+ was started in 2009, but this fork project has since been merged back in to Synergy.
and even screensaver
s can be synchronized.
Architecturally, 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.
It is recommended that if Synergy is not being used on a trusted local network, that all communications be tunneled through a secure encrypted connection, such as through SSH, stunnel
, or a VPN. In this model, the Synergy server computer needs to be running an SSH server, and the Synergy process should be configured to listen only on localhost. To get an SSH server, Macintosh users can enable Remote Access, Linux users can enable sshd, and Windows users can configure an SSH server through Cygwin
. Synergy clients would then execute a command similar to "ssh -L 24800:localhost:24800 user@synergyserver" before connecting the synergy client to localhost.
The concept of sharing keyboard and mouse between computers is still popular according to a Lifehacker.com
article.
Abandoned Project Takeover (APT) system. The owner of the Synergy project (Chris Schoeneman) denied this request two days later. However, this led to the two projects merging two months later, at which point a new website was created under the original Synergy project name.
Computer keyboard
In computing, a keyboard is a typewriter-style keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches...
and mouse between multiple computers. It is used in situations where several PCs
Personal computer
A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...
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
KVM switch
A KVM switch is a hardware device that allows a user to control multiple computers from a single keyboard, video monitor and mouse. Although multiple computers are connected to the KVM, typically a smaller number of computers can be controlled at any given time...
without the video.
Released under the terms of the GNU General Public License
GNU General Public License
The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....
, Synergy is free software
Free software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...
.
The first version of Synergy (created on May 13, 2001 by Chris Schoeneman, also known as "crs") worked with the X Window System
X Window System
The X window system is a computer software system and network protocol that provides a basis for graphical user interfaces and rich input device capability for networked computers...
only, but more recent versions of Synergy support Windows, Mac OS X
Mac OS X
Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...
, Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
and other Unix dialects.
A fork of Synergy named Synergy+ was started in 2009, but this fork project has since been merged back in to Synergy.
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 clipboardClipboard (software)
The clipboard is a software facility that can be used for short-term data storage and/or data transfer between documents or applications, via copy and paste operations...
and even screensaver
Screensaver
A screensaver is a type of computer program initially designed to prevent phosphor burn-in on CRT and plasma computer monitors by blanking the screen or filling it with moving images or patterns when the computer is not in use...
s can be synchronized.
Architecturally, the program is implemented as a server
Server (computing)
In the context of client-server architecture, a server is a computer program running to serve the requests of other programs, the "clients". Thus, the "server" performs some computational task on behalf of "clients"...
which defines which screen-edges lead to which machines, and one or more clients
Client (computing)
A client is an application or system that accesses a service made available by a server. The server is often on another computer system, in which case the client accesses the service by way of a network....
, which connect to the server to offer the use of their desktops. The keyboard and mouse are connected to the server machine.
Network communications
TCP/IP communications (default port 24800) are used to send mouse/keyboard and clipboard events between computers. Communications are not encrypted, and key presses, mouse movements, and clipboard contents sent to Synergy clients can be easily sniffed on network traffic.It is recommended that if Synergy is not being used on a trusted local network, that all communications be tunneled through a secure encrypted connection, such as through SSH, stunnel
Stunnel
Stunnel is an open-source multi-platform computer program, used to provide universal TLS/SSL tunneling service.Stunnel can be used to provide secure encrypted connections for clients or servers that do not speak TLS or SSL natively. It runs on a variety of operating systems , including most...
, or a VPN. In this model, the Synergy server computer needs to be running an SSH server, and the Synergy process should be configured to listen only on localhost. To get an SSH server, Macintosh users can enable Remote Access, Linux users can enable sshd, and Windows users can configure an SSH server through Cygwin
Cygwin
Cygwin is a Unix-like environment and command-line interface for Microsoft Windows. Cygwin provides native integration of Windows-based applications, data, and other system resources with applications, software tools, and data of the Unix-like environment...
. Synergy clients would then execute a command similar to "ssh -L 24800:localhost:24800 user@synergyserver" before connecting the synergy client to localhost.
History
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.The concept of sharing keyboard and mouse between computers is still popular according to a Lifehacker.com
Lifehacker.com
Lifehacker is a weblog about life hacks and software which launched on January 31, 2005. The site is owned by Gawker Media and covers Microsoft Windows, Mac, and Linux programs as well as time-saving tips and tricks. The staff updates the site about 18 times each weekday, with reduced updates on...
article.
Synergy+
On 20 June 2010, a Synergy+ project leader requested that the Synergy+ project take over the original project under the SourceForge.netSourceForge.net
SourceForge is a web-based source code repository. It acts as a centralized location for software developers to control and manage open source software development. The website runs a version of SourceForge Enterprise Edition, forked from the last open-source version available...
Abandoned Project Takeover (APT) system. The owner of the Synergy project (Chris Schoeneman) denied this request two days later. However, this led to the two projects merging two months later, at which point a new website was created under the original Synergy project name.
See also
- Multiseat configuration
- MultiplicityMultiplicity (software)Multiplicity is a computer program that enables one keyboard and mouse to access two or more client computers from a host computer. It was developed for Stardock as part of their ThinkDesk subscription service, but is now available separately....