Malte
You might want to look at the Adobe Flash Media Serves http://www.adobe.com/products/flashmediastreaming/. We used it to prototype a streaming music video service linked to an OpenACS backend and it works quite well especially if you are fluent in Actionscript. There is a developers version available for free and I believe that the free version can be used for non-commercial sites although you are limited to 10 streams.
Be warned, Adobes site is sloooow - everything seems to be done in Flash. I think its a case of "if you have a hammer - everything looks like a nail".
- Steve
