Full install (297 MB download, 1.1 GB installed):Contains all files need for nearly every Tribes mod ever released, including Tribes RPG. Developer friendly.
Minimal install (266 MB download, 680 MB installed):Everything you need to play Tribes RPG.
Dedicated server (170 MB):Only the files needed to host a server. Do not overwrite an existing Tribes with this. This is a standalone server. If you don't need a standalone server, you don't need this.