Adafruit has published a new tutorial to enable you to use Synergy on your Pi.

Synergy is a free and open source software that allows multiple computers to share a mouse and keyboard. One of the computers that the keyboard and mouse is connected to becomes a Synergy server. The other computers becomes Synergy clients. All of this is done over the network. So if your Raspberry Pi is connected to the network somehow (via Ethernet or WiFi), you can setup your Raspberry Pi as a Synergy client so you can remotely control your Raspberry Pi from another computer.

Read more here