Eboard works great for my purposes! I am just using it to look at games. Castling and en passant worked. I didn't try promoting a pawn yet, and I didn't try playing online I did open several games at once. I want to try it for watching live international tournaments, which would be a blast. I think that eboard won't work on icc but just fics (rival chess servers). xboard works on both. But I like eboard quite a bit. Next I'll see if I can load a pgn file somehow...

Edit: I played and won my first 5-minute game on fics.