F.E.A.R. Combat includes the entire multiplayer portion of F.E.A.R. for free. You do need to get a key from http://www.joinfear.com/ to play.
F.E.A.R. Combat features:
- 10 multiplayer game modes.
- 19 multiplayer maps.
- 12 different weapons.
- Punkbuster support for anti-cheat support.
- The capability to download user generated content.