What is the best mouse and keyboard sharing software?

Uses SSL network encryption which is especially important since the shared keyboard data may contain passwords, and the application can "control your computer" (as the MacOS X permissions dialog puts it) it is important to ensure that the connection between computers is secured so that even if you are using it on an open WiFi hotspot, others cannot see the data being sent, nor can they inject data into the connection.

Note: This feature is only included with Synergy Pro and all paid versions of Synergy 2.