Core3 is the working name for the open-source server code. It is the codebase that the SWGEmu developers are constantly working on, and is avaialable for anyone to review, download, and compile.
TC:Nova is the new name of the SWGEmu Test Center Physical Server. Nova works off of Core3. Nove is a testing environment, on which many up and down times, crashes, and tests occur. Players will also notice features such as @ commands (@spice) and Gungan/Jawa Traders, to increase the effectiveness of testing.
Finalizer is the current playtesting SWGEmu Physical Server. Finalizer also works off of Core3. Finalizer does NOT have any player @ commands, Traders, or shortcuts. It will be a testing ground for us to experiment with changes that could be included on the future play server.