From Synergy Wiki
Supported operating systems.
* Windows XP SP3 * Windows Vista SP1 * Windows 7 * Ubuntu 10.04 * Mac OS 10.5 Leopard * Mac OS 10.6 Snow-Leopard * Mac OS 10.7 Lion * Mac OS 10.8 Mountain Lion
We're not actively testing on these platforms, so our software may not work properly.
* Windows 2003 Server * openSUSE * Fedora * Ubuntu 11 and above
We are no longer supporting these platforms due to lack of support for new features.
* Mac OS 10.4 Tiger and below * Windows NT family and below (e.g. 2000, etc) * Windows 95 family and below (e.g. 98/ME)