LOL thats what everyone says, but the Tribes universe was made years before Halo was even thought of. Tribes 2 came out about 6 months before Halo in 2001.
Metaltech: Earthsiege is a mecha-style simulation game developed by Dynamix and released in 1994. Earthsiege is the first in a long line of games set in the same universe which include: Metaltech: Battledrome (1995), Earthsiege 2 (1995), MissionForce: CyberStorm (1997), CyberStorm 2: Corporate Wars (1998), Starsiege (1999), Starsiege: Tribes (1999), Tribes 2 (2001), and Tribes: Vengeance (2004).
From Wikipedia.
Not that I dont like Halo. I played the crap outta that too, but Tribes 2 whipped the sh|t out of it. Massive maps, multiplayer only, and it forced teamwork. Deathmatchers and hotdogs dont fare well in Tribes. Your team will lose. The only similarity I see between them is that they are both futuristic and feature armored players. Beyond that they are vastly different.