Tribes 1 is Free to play and still alive thanks to the community!

Starsiege: Tribes (commonly referred to simply as Tribes) is a sci-fi first-person shooter video game. It is the first of the Tribes video game series and follows the story from Earthsiege and Starsiege. It was developed by Dynamix and published by the company now known as Sierra Entertainment in 1998. 

Tribes was one of the first online-only games of its kind and sported several multiplayer features that other games have only recently included (32+ player support, 128 players max, troop transport vehicles, several different player classes). Most of the standard maps were outdoors in a variety of climates, from sunshine to snow and hail. In general, bases were scattered throughout the map depending on the gametype. The outdoor environments were and still are relatively huge, extending for several kilometers in any direction, but "jetting" and "skiing" gave Tribes a fast-paced feel. 

On July 16, 2007, Sierra Entertainment announced that they would cease online support of Tribes starting on August 16, 2007. However, the master server was still active after this date. As of November 2007, the Sierra Master Server is no longer active, and has been replaced by a community-run master server. 

March 17, 2009, GarageGames announced they have purchased the IP and source code for Starsiege: Tribes and will be releasing an update through the browser based game service, InstantAction. It was announced on May 14th, 2009, that they would soon be accepting email addresses for beta invites. PlayTribes was available for play during the 2009 Penny Arcade Expo at InstantAction's display in the expo hall. 

On October 23, 2010, it was announced that Hi-Rez Studios were the new owners of the Tribes franchise, thus canceling development on PlayTribes. Thus began the development of Tribes Universe, a new MMO, and Tribes: Ascend, a new FPS.