For years, it has been possible to control multiple computers with a single screen, keyboard, and mouse, using a hardware device known as a KVM (Keyboard, Video, Mouse switch). A KVM switch is a great geek tool in itself, and is a wonderful option if you A) want to buy a piece of hardware, or B) only own one monitor. The crappy thing about a KVM is that they all claim to work flawlessly with any type of keyboard/mouse combo (yet never do,) and you can only view one desktop at a time on your single monitor. Most require either tapping a button on the switch itself or hitting a keystroke combination (like scroll lock twice) to switch between computers. (Mac people, you may notice there's no scroll lock key on your keyboard...)
Enter Synergy-- a free, open-source tool that allows you to use one keyboard and mouse to control multiple computers (Mac, PC, Linux/Unix) on multiple monitors, as though they were seamlessly connected.
Sounds cool, you say, but how exactly does it work?
Requirements
Synergy requires that all computers to be controlled together be on the same local network, i.e. they are all plugged into the same switch or on the same wireless network-- since Synergy sends keyboard and mouse commands over a regular old TCP connection. (My suggestion is to opt for a wired connection to avoid latency. A small difference, but a notable difference at times.) Synergy is installed on all computers that will be part of the group-- including the one with the keyboard and mouse attached, and those without. The computer with the main keyboard and mouse is the "server," and the other machines are "clients," that receive keyboard and mouse commands (from you) over the network.
Once Synergy is installed and all computers are talking to one another, the magic happens.
What it Does
As previously mentioned, Synergy allows you to control several computers on several screens, with one keyboard and monitor. When you move your mouse off the left hand side of your main screen, it pops onto the right hand side of the next monitor, and voila-- you are controlling the next computer. No pressing of buttons, no key combinations, and you can see what is going on with all computers at once. The added bonus is that your clipboard contents (i.e. what you are copying and pasting) comes with you as you switch from computer to computer. So in other words, I can copy the body of an e-mail on my PC, and paste it on my Mac. Spiffy.
Limitations
The most surprising thing about Synergy is how well it works-- so long as your network connectivity is up, it works like a champ. (Keep in mind, your internet connection is not required here, just the local network connection between machines.) The synchronization of clipboard contents can be a bit delayed if you are copying a large body of information, but generally just takes a few seconds
By far the least savory part of using Synergy is just the initial setup. The Mac version requires a little command line work and super user access. However, if you know where the Terminal app is located and have used it before, the actual setup is really not that difficult. Configuring the Mac version is a matter of editing the "synergy.conf" text file. The config itself is relatively straightforward, but again, it's not something I could describe to my grandma.
Fortunately for most, the setup for the Windows version has a UI that is a bit more straightforward. I won't get into the particulars here, but fortunately the Synergy folks did-- there is a nice Youtorial-based tutorial to help you through the process, regardless of what OS you are using. Similarly, automatically starting Synergy on login or startup is relatively straightforward in the Windows version, and a bit more confuddled in the Mac or Unix versions.
If you are that guy with 2 computers and a laptop on your desk, and are looking to quit spinning around in your chair, switching between keyboards, definitely give Synergy a try!
