It's quite easy to load games and analyze them in xboard, but I think it would be great to be able to filter the games by commonalities in the tags, such as rating, game length, time control, how the game ended (mate, flag, draw by 50, draw by repetition). And then be able to save the resulting list of games. This interests me in not just for normal chess, but for variants -- since there are _no_ variant database editors I can find.
Is it feasible?