SPECIAL UPDATE DATED 2/7/2011 : Frontier is by no means dead. The development team has hit a few snags and like everyone else, have their own lives to contend with. Please keep in mind that Frontier is a HOBBY project, and is constrained to the free time the developers may or may not have. Further questions should be forwarded to the Development team. Thank you.
In lieu of an expanding thread with no proper OP, here is the un-official Frontier Gamemode thread!
Frontier is a project in the works by forum-goers Jinto, Lazermaniac, Slash, and DApocolypse.
Frontier has a specific art-form to it, with a story revolving around an earth with ever-decreasing resources.
While it is unfortunate that development is not as active as other well known game-modes, the developers have been busy with life, school, and in jinto's case, the gamemode Zinger!, which will be packaged with garrysmod sometime in the near future.
Here is a short FAQ and media posting by Dev DApocolypse