Jabber
eXtensible Messaging and Presence Protocol
"This tool is called HostMaster, and is Bryght's answer to mass hosting Drupal."
I suggested (privately) that they add as a 'proposal idea' support for JEP-0060, which is Publish-Subscribe in Jabber.
Jabber's "a generalized XML message passing protocol optimized for real-time."
"The key to successful networks, and online networks in particular is that they require an object to connect them."
It's probably not the Skype killer that Google Talk will be, but nice to see open standards becoming more popular.
SIP down the road, uses Jabber today, so although the screenshots are all Windows, anybody can connect using a Jabber client.