I am looking for a video streaming server solution, something like online TV server, with ability to make live broadcasts in the internet.

What software could you recommend for that?

What kind of hardware it should run on, should be there anything special?

I am looking for a solution that could be scaled up to at least 1000 simultaneous users online with good resolution of video.

I think it is good to have general answer on what direction to choose. But here more details on my specific case:

• I just looking for a solution almost from scratch. We have some video content that we've produced, but it is not delivered over internet yet.
• We do not tied to any particular vendor for now.
• We want to make 24 hours of steaming three 8 hour blocks with change of content every day.
• We want the ability to make regular live broadcasts.
• I guess we will need to have several options of streaming quality (low ~56 kb/s mid ~273 kb/s).
• Some terms just foreign to me (like play-truncation rate), if you could point out what parameters we should avare of, it would be great.
• Uplink to the internet is to be determined. We plan to start from something and scale up on the way.

If you are already have some kind of media streaming server, just describe its configuration here (hardware, OS, software), peak number of concurrent users it serves. I think it could help people approaching this task.