Here is a list by rigamigician from the group Thematic vote chess. Not sure when the list was last updated though. You can find some really good teams here.
"Here is a list of active groups which focus on specific variations or types of opening such as gambits:
Gambit Fans!, 190 members, 18 vote games in progress
GAMBIT EARS, 54 members, 11 vote games in progress
Londoneers, 56 members, 7 vote games, run by wormrose
1...g6 Modern Defence, 127 members, 6 vote games, run by wormrose
Pirc Defense Group, 92 members, 6 vote games, run by wormrose
KIA inc., 71 members, 6 vote games, run by wormrose & Billium248
King's Gambit Players, 1126 members, 5 vote games in progress
1.g3 Benko/Hungarian, 26 members, 5 vote games, run by wormrose
1.b3 Nimzo-Larsen Attack, 168 members, 4 vote games, run by linksspringer & wormrose
1...b6, 78 members, 4 vote games, run by linksspringer & wormrose
Benoni Counter-Blast, 62 members, 4 vote games in progress
English Opening Lovers, 211 members, 3 vote games in progress
1.e4 d5 Scandinavian Defense, 149 members, 3 vote games in progress
Bogolyubov Variations, 115 members, 3 vote games in progress
Budapest Gambiteers, 75 members, 3 vote games, run by polleke
Sicilian Dragon and his systems, 70 members, 3 games in progress
Caro-Kann Cutthroats, 297 members, 2 vote games, run by polleke
Bird's Opening Lovers, 230 members, 2 vote games, run by linksspringer & wormrose
Alapin Variations, 166 members, 2 vote games in progress
The Radical Ruy Lopez, 165 members, 2 vote games in progress
1.d4 Nf6 Indians, 155 members, 2 vote games in progress
Grunfeld and the KID, 77 members, 2 vote games in progress
Gambit Gang, 311 members, 1 Latvian Gambit game, run by rigamagician
Dynamic Dutch Defense, 128 members, 1 vote game in progress
1.Nc3 1...Nc6 Fans!, 62 members, 1 vote game, run by linksspringer
Sac and Attack, 45 members, 1 Peresypkin's Sacrifice game, run by rigamagician
Hippo, 34 members, 1 vote game in progress"
I recently got the bright(?) idea to replace Fritz 12's opening book (about 1.5 million games, and several years out-of-date) with my ChessBase BIG DB (about 5.5 million games, up-to-date via TWIC).
So, now there's hardly any difference between the "Book" output and the "reference" output, I presume the book was originally intended to be a smaller and more exclusive DB intended to reflect current theory more so than a much bigger DB that basically has everything but the kitchen sink thrown in.
Does anyone familiar with chess software have any thoughts on how "bright" my idea was? I'm mostly using F12 to analyze my finished games and considering my mediocre tactical ability maybe worrying about how well the software critiques my openings is a waste of time...