What are the various desktop streaming software used by justin.tv and similar sites? I want to create a channel to which various users could stream their desktop. I’m looking for the best solution for them.

So far I’ve found Dyyno (free but too simple), WireCast (expensive and too complex), and Flash Media Live Encoder (free).

I need one that is free, simple to use, yet powerful enough (notably, it must be able to stream a specific area of the screen, and to include audio from the software or from the microphone or both, and to run on both Windows and Mac OS X).

Do you have any suggestions?

P.S. LiveStream and Ustream have proprietary solutions (incompatible with others).
If you want to stream with Justin.TV, you can download FFSplit !

http://www.ffsplit.com/

It is still in a BETA State, but it does run quite well !

Don't forget to follow every instruction that is put on the site.

Good luck !