Sockets

Hi to all! I've a problem (and a doubt). I'm trying to find out where php_sockets.dll file is! I'm trying to develop a proxy server in PHP and I need sockets functions in PHP. I downloaded the latest distribution of PHP binaries and there is no php_sockets.dll in the extensions directory; I've searched all over the Internet, and can't find it. I'll really appreciate if you can help me! By the way, is PHP's sockets funcions usable? (because they are in an experimental phase I believe). Thank you very much in advance!