FSEventer uses Spotlight’s indexing framework to provide real-time, system-wide file monitoring. This means that any time you create, alter, or move any file on your hard drive, FSEventer will register a “file system event” and immediately display the change in an attractive file tree. FSEventer can display up to 80 recent file events, and labels each with its time of occurrence and originating process or application.

Its massive entertainment factor aside, FSEventer is an extremely valuable diagnostic tool. If you’re about to open a shady installer package and want to know exactly what it will copy to your hard drive, run FSEventer during the install. You’ll see the file tree display explode, revealing the location of every new file. If you’re experiencing slow disk response or can’t determine the source of a performance hit, use FSEventer to identify processes that are regularly writing to your hard drive.

Because FSEventer relies on OS X’s existing indexing framework, it is surprisingly easy on your processor and RAM. Even during the fastest batch file operations my MacBook Pro could muster, FSEventer wouldn’t top 20% CPU or 25 MB RAM. Its low RAM footprint means you could conceivably run this utility permanently in the background and use it to find lost files or undo mistakes you’ve made with system files.

FSEventer doesn’t offer many flashy features to complement its main function, but this pays dividends in usability. FSEventer is already a power tool – it doesn’t need bells and whistles as well.

FSEventer is donationware by Robert Pointon, and runs on both PPC and Intel Macs.