Synergy lets you easily share a single mouse and keyboard between multiple computers with different operating systems, each with its own display, without special hardware.
You tell synergy how many screens you have and their positions relative to one another. Synergy then detects when the mouse moves off the edge of a screen and jumps it instantly to the neighboring screen. The keyboard works normally on each screen; input goes to whichever screen has the cursor. All the computers on your desktop form a single virtual screen.
Just copy any text, HTML, or image on one screen and then switch to another screen and paste it. It’s as if all your computers shared a single clipboard.
With synergy all your screen savers act in concert. They start and stop together. And, if you require a password to unlock the screen, you’ll only have to enter a password on one screen.
Synergy is open source and released under the GNU Public License (GPL). It is a great tool for users with multiple computers on their desk since each system uses its own monitor.