Forum OpenACS Q&A: Response to live communication & dotLRN...

dotLRN will include a number of well-known packages (bboard,
faq, survey, calendar), and a fairly detailed architecture for
adding your own applications (applets in dotLRN-speak). If you
want to add a live classroom integration package, you're going to
have the hooks to do that.

That said, doing true live classroom integration is hard, with or
without dotLRN. But if you find a good way to do it, dotLRN can
and will support that type of integration.