Robot Battle Links
Helpful "101 guides" and other RB tips. Publicly editable.
Home of the Random Environment Contest (REC), the Tag Team Tournament (T4), and the All In, Last Out (AILO) contest.
A list of upcoming and currently running contests can be found here. As well as links to many useful sites. Also see Ville Saalo's page describing various helpful tips and tricks for RB.
Many robots and utilities available for download. Not very well organized, but full of older example robots. Largely replaced by the Robot Battle Registry.
Various tools for Robot Battle, including a tournament tool, editor, and an updated robot scrambler.