In the world of online video, specifically flash based video, there are very few choices when it comes to serving. On one hand you have the Adobe Flash Media Server with a pricing model which makes you think "yeah, whatever" , then we have the Wowza Media Server which still relatively new has a better pricing model, but still far too expensive in todays age of free and open source software. Finally you have the Red5 Media Server which is completely free.
Generally I stay away from open source products, only because I usually find them buggy, and there are so many people working on it, its hard to maintain a stable version.. For MeBeam the majority of our network is built on proprietary technology, consisting of several types of servers, working together..
For my friends who know me, I am first an assembler programmer and then C; so I'm very much into pushing the speed limits of what the technology of a given day can do - this is the curse of guys who had their start in development, making games in the day of the commodore 64 - never being satisfied, forever tweaking code, trying to squeeze every last possible cycle from their processors..
I've always considered, Java a toy - a proto-typing language at best - but recently, some people who I have been working with, especially Steven Gong who is one of the guys from the Red5 development team, has really impressed me, with what they are achieving using Java.
Red5 is an open-source alternative to the Flash Media Server, and can do pretty much was FMS can do, but it's completely free.. Recently the guys from Red5, have been working on clustering technology, which is a fancy word for joining several servers together to act as one super server..
If you are a developer, and interested in getting into online video, I give the Red5 boys, two thumbs up;