Gmail's voice and video chat now supports the main Jingle standards, XEP-166 and XEP-167.
And there are two open source implementations that it works with:
http://code.google.com/p/libjingle http://telepathy.freedesktop.org/wiki/
And there are two open source implementations that it works with:
http://code.google.com/p/libjingle http://telepathy.freedesktop.org/wiki/
Thanks for the clarification on the standards, it seems to have evolved since the early days.