Is there any possiblity to share our system screen using this plugin.. It will be greatly useful for ppl to give presentations and for online teachin,...

it doesn't work for me, it shows so many errors

there is no problem in elgg 1.7.15 it works nice
in elgg 1.8.5 no way  no settings and many errors.
is there a version for 1.8.5 in development?

Current versions were released for Elgg 1.8.1 and are currently being upgraded to work on more recent versions. Upgrades will be released when ready.

Follow us on Twitter / Facebook to see when updates are released:
http://twitter.com/videowhisper
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Screen sharing is possible with external tools as explained on:
http://www.videochat-scripts.com/screen-sharing-with-flash-video-chat-software/