i'm using cometchat , and It's really good : http://www.cometchat.com/?r=7790

I've started using AVChat which has audio and video chat as well as an HTML overlay for Apple and phone users. You will have to have some form of flash media server to run it, though. I use Red5.

While I use a lot of DBTech products, I've always liked cybchat for its simplicity. I'm sure if my users start using it more often, I'll look into something fancier. But for now, I like being able to customize the templates quickly.

FWIW, I'm still using ProChatRooms on my site. The company has gone away and there's still no support, but I have to say that I've not had a problem with it -- it just runs -- and we periodically have 12-15 people in it. While I didn't speak well of it 5 years ago, I can honestly say that it's been trouble-free for the past 5 years. The only maintenance I do with it is clear out the chat transaction log once a year, after which I refresh the MySQL databases on the site.

I originally purchased it because it had file/photo uploading and options to add video chat. I eventually added that and it worked very well. However, as the streaming server was hosted by ProChatRooms and the company has gone away, I've disabled the video setup -- someday I may examine it and try it again with some other streaming host. In a survey from our members, few of them ever tried the video chat, so not having it is no disadvantage.