Source on Multicast Connection in C

[frankly]

Hi ppl,

Anyone knows where I can get some source on multicast programming in C? I've been searching on google for quite a few hrs...nth came up....Maybe my searching method has some problems....and also I'd like to ask, for a program to use multicast in sending and receiving, as in many other networking programs, they have to listen and accept at the same time, so what would be the best to use in this case (multicast). fork or thread is better? Just wanna wrap up the idea first.

Thanz!!
_________________
fRaNkLy i'm FrAnKy