Pacifist is one of the utilities that any MAC user must ever wished to have. Pacifist is a Cocoa application that opens up .pkg installer packages and lets you install or extract individual files out of them. It is also able to open a variety of other formats, including .mpkg metapackages, .dmg disk images, and .tar, .tgz, and .tar.gz archives.
Pacifist can come in handy if you need to install just one file out of a package instead of the entire package. For example, if your copy of Sherlock gets damaged and you need to reinstall it, but don’t want to go to the trouble of reinstalling the entire operating system, you can use Pacifist to extract only what you need from the install packages. Pacifist can also be used instead of the normal Installer, which can be helpful if you experience bugs in the Installer that mess up your symbolic links, or if you just like a little more control over the installation process.
Pacifist also includes the ability to verify existing intallations, comparing the files on your hard disk with the files listed in the package, and notifying you of missing files as well as files that have different permissions or checksums than those listed in the package*. Pacifist is also able to scan through your receipts for kernel extensions, and compare them against the kernel extensions you have installed, so that you can see what kernel extensions in your System folder have been installed by third-party applications. Pacifist also includes the ability to update prebinding information, either for the entire hard disk, or for an individual folder (although updating the prebinding information is not necessary in Mac OS X 10.4 “Tiger” and higher, and is not as necessary in Mac OS X 10.2 “Jaguar” and higher as it was in earlier versions of Mac OS X).