Originally Posted by bobber205
Will much of what I learn trying to program X with Xcode and the X11 server in OS X carry over to linux?
depends on what toolkit of you are using. If you are doing X programming itself then yes you will probably be able to keep a few things (as most X implementations are similar).
If you are using a toolkit such as GTK then yes you will be able to keep the experience because they are the same on all platforms.
Why would you want to do X11 development anyway? Why not just use a cross platform toolkit like QT?