By looking in the programs instalation folder (while trying to enable HTTP Proxy) I found out these familiar DLLs:
Those DLLs are part of oggcodecs! thus meaning that they use oggcodecs, or?
Although they mention Theora in Settings page:
while trying to use Video Chat an Adobe Flash window was opened. Video Chat is done using Adobe Flash!
I've tried to enable Theora Video Chat but failed, the above mentioned DLLs are not even loaded by the process.
They mention Xiph.org, CSIRO and Zentaro Kavanagh in About dialog, but I don't know how they use Theora codec: