Some more useful links for those who are interested to learn more:

BWAPI GitHub page [0]

StarCraft Broodwar AI development Wiki[1]

The obligatory IRC channel where we discuss random topics concerning AI development[2]

[0] https://github.com/bwapi/bwapi

[1] http://www.starcraftai.com/wiki/Main_Page

[2] http://webchat.freenode.net/?channels=BWAPI