Mac OS X Applications, tend to be limited due to the UNIX “open” nature of the operating system. Contrary to Windows for example, where one could bury an entry into the Registry under any name, provided you’re given Admin privileges (which is very natural in Windows).
Under OS X, applications are forced to use dedicated locations for storing settings and preferences. ~/Library and /Library.
With that being said, this doesn’t stop some applications to use other mechanisms in conjunction with that.
I cannot name them all primary because I don’t know all of the existing ways, but I can tell you some common forms:
Serial Number / License Key: These are the typical. The program stores an “encrypted” copy of these values in its preferences (sometimes even unencrypted), usually located in:
- ~/Library/Preferences or /Library
- The Application Bundle itself
- Some value in the user’s Home folder (possibly hidden by a .)
The problem with these are obvious, the serials get published/shared/copied and you have no way to stop it. Some applications have a “blacklist” of serials that although perfectly formatted, are internally hardcoded to be bad.
Online Activation: Less common (and usually more annoying), these require the app to connect to an online host to “activate” or “validate” the license. This prevents a lot of fraud and usually ends with the application cracked by some genius, where the code that does the validation is simply modified to always return “ok” making the application believe that the internet stuff went ok. Read: Adobe Products.
In any case, the program has to store the value somewhere, and the usual locations apply.
Tied with Hardware ID This is common too, they extract your drive’s serial number and some other parameters (Network card MAC Address for example) and they create a serial number that checks for those. So even if you “copy” the license, the new machine won’t have the same values and it will fail. This is annoying because if your hard drive crashes and you boot from a backup, you’ll have to re-register.
RESOURCES
I assume you want to continue reading about this, so instead of believing me, follow these links:
Best Answer
Delete Old DRM Copies of iTunes Music and Download DRM-Free Versions
If you purchased any music from iTunes between 2003 and 2009, you downloaded tracks with DRM (Digital Rights Management) in them. Apple's long since removed the DRM, but you might not have. Wired shows how to update your music library with the new, DRM-free versions.
The process here is pretty simple, but if you're anything like me, you never bothered to actually do it:
Scroll down to find 'Protected AAC audio file' as a Kind - those are the ones you need to replace.
Once you run through the process of deleting those songs you can download them from the cloud at any point, DRM free. This has been around for a while, but if you haven't grabbed those DRM free versions, now's as good a time as any.
Source: Lifehacker Delete Old DRM Copies of iTunes Music and Download DRM-Free Versions
Also see - Which songs in my iTunes library are DRM protected?