Halo 3 Epsilon

From Halopedia, the Halo wiki

A Gamercard demonstrating one of the first players of Halo 3 Epsilon.

Halo 3 Epsilon[1] is an internal-only Halo 3 build.

It was released to Microsoft employees as of August 10, 2007, and featured campaign (single-player and cooperative gameplay both), Forge, and multiplayer modes[2][3].

Halo 3 Epsilon was confirmed to some degree later on August 10th by Bungie Studios on a Bungie Podcast. Microsoft employees, Xbox.com representatives, and the Bungie Studios staff have been playing it, and Bungie employees are using this build to finish the final details of the game.

References

The Email Sent To Employees of Microsoft about Epsilon.

Congratulations on being selected to participate in the Halo 3 Epsilon! The Epsilon is now available for download on Marketplace!

First, unlike the Alpha, Beta or Delta, this is a very special test in that not only will you be testing nearly final Halo 3 Matchmaking, you will also be able to:

  • Play Multiplayer on six maps: Snowbound, High Ground, Valhalla, Last Resort, Epitaph and our new big map, Sandtrap.
  • Play Custom Games and test out full game variant editing.
  • Play with the Forge and be able to cooperatively edit and save multiplayer map variants.
  • Play up to 4 person co-op on a single Campaign level.
  • Play and test the full Saved Film functionality, including screenshots you can view in-game for Campaign, Multiplayer and Forge.