Mozilla Firefox is a great web browser, however it does have drawbacks, namely it is loves to eat up memory. Firefox has always been affected by this issue and memory leaks are one of the issues that needs to be resolved in order to attract more users.
Firemin is a small app that runs from the system tray and tries to address the problems associated with Firefox’s memory hogging ways. It works with XP, Vista, Windows 7, and Windows 8, and runs on both 32 and 64-bit versions.
Due to Firefox’s memory leakage, Firemin runs the clean memory API call a few times per second, rather than Windows Memory Management which performs similar operations less frequently.
Many would argue that Firemin is not a proven app and the benefits of using it cannot be quantified. That being said, the app is Open Source and free to use, so if it works for you then great! If you would rather rely on Windows Memory Management to periodically scan running processes and request them to release unused memory, then simply choose Windows to manage it.