6 links
10/5 Mapmakers
numbera.com
Offering map downloads and information on the OBED Marathon level editor.
Marathon Open Source
source.bungie.org
Microsoft's own Open Source Initiative, using the GPL'ed Marathon 2 source code, called Aleph One.
Marathon Resurrection
planetunreal.com
A total conversion for Unreal Tournament in the spirit of Marathon, by Team Unpfhorgiven.
Marathon's Story
marathon.bungie.org
Houses the full text of the game series with discussion and speculation.
The Battle Cat's Marathon Page
ebwonks.org
Find original Marathon maps, films, Forge tips, and related humor here.