We used to use Borgchat. It was fun, because there were lots of animated characters you could add to a message to add emphasis or just to make the day a bit more exciting. But it crashed all of the time and was not dependable. We switched to Sidenotes by Blue Note Software. It is not free (about $150) but it has worked flawlessly since installation. We have it on 20 computers and have used it for about 3 years now. Not as much fun as Borgchat, but we all have to grow up sometime
