[lug] online meeting software for linux

[Davide Del Vento]

Hi,
I was wondering if there is any software that would allow me to have
an "online" meeting, that is, I have a speaker (say myself)
"projecting" my slides (and possibly desktop, e.g. shell or other
stuff) and talking. Ideally people would be able to watch me realtime
in a browser. In a perfect world they would be able to pose questions,
but I understand that would be too much for me to ask in this world
:-)
Seeing without hearing would be ok. Installing a custom software such
a VNC-client would be ok too, but only if it's open source.

So, what I've found so far is a large bunch of *services* (most of
which are paid, although a few offer a basic free version, or a short
free trial) which do offer what I want as a service, often requiring
the installation of closed software on either client or server or
both. But I don't want a service at all. I want a software to
configure and run on my machine(s). I'm imaging it as using a (very
beefed) server, which would do the number crunching for the
compression and would run the actual broadcast server (is apache ok?)
and a tiny client on the speaker machine that would just send
screenshots diffs to the server (in the same LAN). I am not Google, so
I don't need the stuff to scale to millions. Just one speaker and a
few dozen attendees.

Among the software category, I haven't found exactly what I want,
these are what I've found:

1) instanbul (only records, does not stream realtime and it is very
hard on the speaker machine, which is bad - I guess with some work it
could be offloaded to the server)

2) fluendo (not sure what this exactly is)

3) peercast (it seemed exactly what I needed, but it looks dead)

4) geekcast (it seems to be a front-end to peercast, thus not usable)

5) icecast (it only stream audio, not video/slides)

5) cygnal (my understanding this is just a todo list, not an actual
running software)

Am I wrong with any of these? Anything else that I should look into?
Has anybody tried anything like this and succeeded/given-up?

Thanks,
Davide