Japanese anime studio responsible for such classic series such as Cowboy Bebop, Vision of Escaflowne, Rahxephon, Angelic Layer and lately Wolf's Rain. The studio, which was founded in 1998 by former Sunrise producer Minami Masahiko (Cowboy Bebop, Escaflowne, Wataru, etc), resides in Tokyo's Suginami ward. In fact, a lot of the main names at Bones where formerly working at Sunrise, so you see a lot of similarities between their works, and even some title overlap.
Bones is active in all kinds of anime productions, be it TV, OVA, game or theatrical productions. At first they just co-produced their anime with other companies, but since Rahxephon they have also created anime of their own. And thus far, all the series they worked on were of a very high quality both in respect to animation as well as in creating an interesting story and characters and therefore managed to create a huge fan base waiting for the next Bones release. Their current release, Wolf's Rain was eagerly awaited and after the first couple of episodes promises to be all that.
Some links:
http://www.ex.org/5.4/04-feature_bones.html
http://www.bones.co.jp