Icecast will stream both.  The PHP-shout package is used to prepare the 
stream and send it to the icecast server.  I was able to get it to 
stream an .ogg video (with sound).  I didn't look into mp4 at the time.  
According to their homepage (www.icecast.org), icecast 2.2.0 will stream 
theora video with alpha4 or later libtheora.

Ok ... after some more googling, it looks this this may not be 
suitable.  As far as I can tell, the only video format supported would 
be theora.  You could always do something like:

ffmpeg2theora original.mov -o new.ogg

for each stream you want to send, but this would also require your users 
to have .ogg players.  Sorry for the wild goose chase!

Josh

admin at lctn.org wrote:
>> I recently went through some pains to play with setting up a streaming
>> server with Icecast/PHP-shout (both GPL).  Icecast also has a nice Ices
>> broadcast component that works well with Icecast (but did not stream
>> Theoris at the time I played with it).  The notes I took are a bit
>> scattered, but may be helpful.  You can read them at:
>>
>> http://www.radkeland.org/setting-streaming-webserver-fedora-core-6
>>     
>
>
>
> I haven't looked at your link yet, but isn't Icecast audio only? I am
> streaming video.
>
>