[samjesse]

To summarize what I understand. Please let me know if I got it.

Many stream format can be sent from the server. If the client computer associates this format with a player, then will that player fire up and play the stream.
No matter how good a stream format is, if the client does not have the correct associated player, it will not play.
And since I can not control the client machine and install a direct show filter on each one, I better not use OGG, AAC or SPX or did I read somewhere that any Flash-based player can play them?
and since most of the computers have a Flash-based player, then I will be safe to use any of these 3 formats?