Legions: Overdrive is a "spiritual successor" to Tribes, borrowing gameplay elements from the series such as skiing and jetpacks. It's completely free and supports modding, user-hosted servers and more.
Remember playing this game on the web-site along with Marble Blast, Aces of Skies (?) etc. Great Memories. The game is easy to learn but hard to master similar like to Tribes but easier.
Good job keeping it alive!