Brood War

BW Programmers
Forum boards focused on the development of tools and 3rd party programs.
http://bwprogrammers.com/

BWChart
Tools with uses such as in-game coaching, the ability to add audio to replays, and a replay analyzer.
http://www.bwchart.com/

BWCL.de
League competition with multiple divisions.
http://broodwar.ingame.de/bwcl/

Fighter Replays
Upload and Share StarCraft: BroodWar Replays
http://fighterreplays.com/starcraft

International Cyber Cup
Ladder, non-b.net, based on individual and team competition.
http://www.iccup.com

WGTour.com
Competitive ladder focused on 1v1 and team competition.
http://www.wgtour.com

Wikipedia: BroodWar
General information.
http://en.wikipedia.org/wiki/StarCraft:_Brood_War