Empathy - Apps/Empathy - GNOME Wiki!
Whereby (formerly appear.in) - Collaborate from anywhere - video meetings with no downloads
IM+ - Chat everywhere! IM+ is the most widely used mobile IM app! Connect all-in-one to MSN, Yahoo!, Goo...
Around.co - Around.co is an app that provides video calls to remote teams all around the world.
Pinger - Pinger lets you text and talk free with the people you care about most, anywhere on the planet.
Remote Meeting - Remote Meeting with Video, Voice, Chat and Screen Sharing