who can offer me a opensource server example for study

[succulent_lily]

i want to learn some tech about server，such as multithread ，socket，and so on
but the example is so simply
so i want to find some opensource software for study
but it is hard to find it
who can give me some useful message.thanks

[jpn]

What kind of server software? Have you seen the networking examples (http://doc.trolltech.com/4.4/examples.html#network) of Qt?