KansaiRobot: Your sockets programming knowledge, gained from linux, should serve you just as well, while developing on a mac. Beautiful part of Berkely Sockets is that "sockets" is very portable interface/library between all the 'nix. And yes, I would definitely include OS X in that category of 'nix. While the XCode and Apple Tools on Mac are very nice and feature rich, like everything worth while, it'll take a couple hours of "playing" with to get your bearings on where everything is, and how somethings are done differently when developing with Xcode.
Now, while I said you can program on OsX using a Berkely Sockets interface, there are other network programming interfaces that work equally well, but you might not be interested in those, if you already have momentum towards the Berkely Sockets (Linux Network programming style).