more categories

Gaelcon (43)	Warpcon (54)	Vaticon (8)	Dominicon (8)
ConFESS (4)	Sillicon (6)	Moo-Con (0)	K2 (0)
Leamhcon (1)	Leprecon (16)	Ubercon (0)	Origins (1)
Itzacon (13)	Q-Con (2)

Mambo is Free Software released under the GNU/GPL License.