it's difficult and i wouldn't recommend it to newbies i.e., it is an entirely forgivable sin for leftists (pacifica listeners) to use microsoft products.
however, at the server end, alternatives are available. i will have to look at what pacifica's setup is, to see if it requires microsoft specific features, but even before i do, i can safely claim that the capabilities listed in their web page can be achieved through a combination of open standards (HTTP, RTSP, SMIL, MP3, etc -- of course there are some issues surrounding mp3 encoding as an open standard) and software that supports it.
--ravi