Now that Adobe has published the specifications for the FLV format I wonder if someone smarter than me can write an open source alternative to Flash Media Server? As Tinic Uro writes the format is essentially AMF, so with AMFPHP out there it might be just a small step to extend this to Video - though my expertise in this area is to little to judge how difficult this would be.

Note: I must have been living in the woods during the last months - the red5 project is working exactly on that and it looks like they have gotten pretty far already - that's great news!