After that, then it depends on which sources you want to build. I
don't think anyone is really using XCode much.
I wouldn't say that. Xcode is perfectly suited for developing and
debugging pd externals (among other things).
I can offer an xcode template which is made to be used for flext-
based externals.
https://svn.grrrr.org/ext/trunk/flext/examples/xcode-template/
However, apart from the library dependence (which you could just
delete) it should work for any Pd (and also Max/MSP) external.
gr~~~