Playing Multiple Audio streams

[Jeff McBride]

Hello,


Are there any good ways to play several audio sources simultaneously? If
an application wants to be playing say, several wave files overtop of each
other, does it have to mix them itself and then play one stream. Or are
there other drives, or possibly a daemon of some kind to do it? 

And how about multiple applications that are unaware of each other playing
at the same time? 


Thanks for any help,

Jeff