As others have said, Synergy's problems are not technical but management. The guy who runs Symless isn't terribly good at business, no offense to him. the product is chronically mismanaged. Multiplicity from StarDock is Windows only but manages everything Apple's product does, too. There are open source VNC apps that handle copy/paste and DnD, it shouldn't be hard to at least look at that code as a guide, but without a good developer, Symless is rudderless.