Via the game’s Wikipedia page:
Dear Esther is an experimental “ghost story” computer game developed by indie game developer thechineseroom. It was first released on July 29, 2008 as a free Source engine mod, and is currently being remade for a commercial release on Steam on February 14, 2012.
The player progresses through the plot of Dear Esther via a series of voiced-over letter fragments to a woman named Esther. The game does not directly specify who the narrator is, but there are suggestions he is Esther’s husband and that she is dead, killed in an automobile accident.
Looks beautiful. This started as a mod and now finding it’s way into becoming a full-blown game.