
There are times when a directory needs watched. For reasons of its own, a program may need to know when a file is deleted, updated or renamed. If .NET is involved, this is a trivial task. Create an instance of the FileSystemWatcher; set some properties, and the task is completed. If a non .NET solution is required (and regardless of the hype, some people haven't embraced .NET in all of its glory.), the ReadDirectoryChangesW function must be used, however the documentation for ReadDirectoryChangesW is sketchy at best.
I'd kinda like to see FAM supported in kernel on all platforms, especially for those that use gconf as it seems to make the biggest impact there on my OBSD system (no FAM) compared to my Gentoo system (FAM). Gnome-VFS (can) use(s) FAM, and frankly I like it from an app devellopment point of view.
http://oss.sgi.com/projects/fam/