Probably the most important research resource for any underground metal fan. The settler of many arguments. The ability to follow links from band members to their other projects is incredible, like an internet version of looking at the shout-outs in album liner notes for mentioned bands as hints at who to check out next.
This is how many people have used Discogs.com . You can drill-down into the individual artists which make up a band/collective and see who else they work with or share a label with.