Uninstalling Packages (from pkg or mpkg files)

There is no package manager in OS X. See Dr. Smoke's FAQ.

You might also try third party apps at www.versiontracker.com such as AppZapper.

Not that I've heard, and I hope they never try to implement one. Providing methods for clean uninstalls is the responsibility of the developer, not the OS, and it is impossible for the OS to do so in a way that cannot be circumvented or frustrated by a lazy developer.

Are you looking for a Unix package manager or something for OS X to simply uninstall applications? Your request is rather unclear in this regard.

Uninstalling applications in OS X is pretty straight forward, and as Wade has indicated there are several third-party utilities to help with the process. However, it's easy enough without third-party software. Wade gave you a good link to check out. Here's some additional info:

Uninstalling Software: The Basics

Most OS X applications are completely self-contained "packages" that can be uninstalled by simply dragging the application to the Trash. Most applications create preference files which are stored in the /Home/Library/Preferences/ folder. Although they do nothing once you delete the associated application, they do take up some disk space. If you want you can located them in the above location and delete them, too.

Some applications may install an uninstaller program that can be used to remove the application. In some cases the uninstaller may be part of the application's installer, and is invoked by clicking on a Customize button that will appear during the install process.

Some applications may install components in the /Home/Library/Applications Support/ folder. You can also check there to see if the application has created a folder. You can also delete the folder that's in the Applications Support folder. Again, they don't do anything but take up disk space once the application is trashed.

Some applications may install a startupitem or a Log In item. Startupitems are usually installed in the /Library/StartupItems/ folder and less often in the /Home/Library/StartupItems/ folder. Log In Items are set in the Accounts preferences. Open System Preferences, click on the Accounts icon, then click on the LogIn Items tab. Locate the item in the list for the application you want to remove and click on the "-" button to delete it from the list.

If an application installs any other files the best way to track them down is to do a Finder search using the application name or the developer name as the search term.

There are also several shareware utilities that can uninstall applications:

AppZapper 1.6
AppDelete
CleanApp
Yank 1.31
SuperPop 1.0b2
Uninstaller 1.99
Spring Cleaning 8.0

For more information visit The XLab FAQs and read the FAQ on removing software.

If your query is for a Unix package manager then I believe you want to check into Fink. There is a version available for OS X.

If the application cannot be cleanly uninstalled by dragging it to the trash, the developer should provide an uninstaller. If this is not the case, the next step is to send a scathing e-mail to the developer, calling them things like "unprofessional" and the like. Too many developers give too little attention to installers/uninstallers, when it should be a serious portion of development. (Can anybody tell that I write installs/uninstalls for a living?)

I think Wade has described it pretty well. The packages you are referring to are generally installers. A .mpkg is a "Master" package meaning that it installs more than one package, usually at the option of the user. OS X applications are themselves packages as you mentioned.

If a installer actually installs needed files in folders that would not normally be benign if left orphaned (like a preference file) then the developer should provide a specialized uninstaller. It's poor programming to install something, say, in the Extensions or StartupItems folders and not provide a means to remove them if the application itself is discarded.

If you follow Wade's and my suggestions you can easily uninstall any application that does not include an uninstaller. You needn't rely on the package receipt. Besides, not all third-party software even installs a receipt.

Package receipts are provided by the installer only if the developer includes one. I have dozens of applications installed on my system that had no receipts installed. If you read the Developer documentation on the use of receipts you will find that this is not automatically performed by either the OS or the installer.

Apple doesn't supply uninstallers (most of the time) because they don't intend for you to uninstall system software and upgrades. You cannot simply uninstall OS X. As for applications they are contained in packages and rarely ever install anything that isn't benign if the app is deleted. However, Apple has on occasion provided means for uninstalling versions of QuickTime by issuing separate uninstallers. There are only two ways to uninstall a version of OS X: Erase and Install or Archive and Install.

Hmm, I thought my message on how to uninstall applications was pretty thorough. I'm not sure how you would fail to miss any remaining components if you followed the suggestions I provided. They weren't "guidance", but procedures. If I've been unclear about anything please let me know.