> packaged as a .pkg, which makes it really easy to cleanly erase installed software. In theory, but there's no package uninstaller and OS X installer packages

> packaged as a .pkg, which makes it really easy to cleanly erase installed software. In theory, but there's no package uninstaller and OS X installer packages are neither pure nor idempotent. While you can remove the files installed by one, there's no straightforward or platform-provided way to undo the changes made by their (generally unknowable) install scripts. Incidentally, Apple shipped an Xcode uninstaller; written in perl, it used lsbom and pkgutil to collect and subsequently remove the files owned by all the com.apple.dt packages complement the system-owned files or files installed by other packages.