As I already mentioned here a while ago, Wengo, a subsidiary of telecom operator Neuf Telecom, is now one of Disruptive Innovations' customers. We started working with them on a XULization of their OpenWengo product, an excellent SIP-based softphone with video and chat.

Don't ask if we're building an extension to Firefox. We are :-) Stay tuned ! Standard protocols and open source, you are going to love it !