From the Mac Developer Library:
Third-party frameworks can go in a number of different file-system locations, depending on certain factors.
- Most public frameworks should be installed at the local level in /Library/Frameworks.
- If your framework should only be used by a single user, you can install it in the ~/Library/Frameworks subdirectory of the current user; however, this option should be avoided if possible.
- If they are to be used across a local area network, they can be installed in /Network/Library/Frameworks; however, this option should be avoided if possible.
For nearly all cases, installing your frameworks in /Library/Frameworks is the best choice. Frameworks in this location are discovered automatically by the compiler at compile time and the dynamic linker at runtime. Applications that link to frameworks in other directories, such as ~/Library/Frameworks or /Network/Library/Frameworks, must specify the exact path to the framework at build time so that the dynamic linker can find it. If the path changes (as it might for a user home directory), the dynamic linker may be unable to find the framework.