What Is Darwin (and How It Powers Mac OS X)
Subject:   Tweaking kernel
Date:   2005-09-29 05:29:05
From:   Mafretete
Response to: Tweaking kernel

Yes, you can replace the Mac OS X kernel and compile one yourself. For example, it was not possible to spoof your MAC address with Mac OS X <= 10.3, but you could modify the Darwin source code to allow this and use the recompiled kernel with Mac OS X.