Convergence was created by the North American net.goth community to be an answer to the UK's gatherings at Whitby. Each year, the various sites that wish to host a Convergence put up their bid websites, and net.goths from alt.gothic flame each other and the various committees to a crisp before voting on the site that will get to host the next year's Convergence.
Convergence is at its core a party for the alt.gothic newsgroup, but later ones have welcomed those net.goths who mainly follow mailing lists, LiveJournal and even MySpace. Convergence 7 caused much controversy by advertising in the Village Voice, and by being run by Cliff Low, a notorious (in the mid/late-90s NYC goth scene, anyway), socially inept greaseball.
Convergence itself is half convention, half party. There are bands and other forms of live entertainment, occasional celebrities stopping by (i.e., Jhonen Vasquez showing up at C3, and Peter Murphy's surprise appearance at C6), fashion shows, and all manner of vendors hawking all material things associated with goth subculture (except for drugs, but then, the venues that host Convergences often maintain well-stocked bars). DJs from around the world appear and spin sets for dancing, which makes up the bulk of the evenings during Convergence when the bands aren't playing.
Convergences past, present and future: