FAM provides an API applications can use to be notified when specific files or directories are changed. It is intended to be a more efficient and more useful replacement for alternatives such as the poll and select system calls.
FAM is most useful for tools such as graphical file managers, which should always show the current state of the system, even if another tool is used to modify a file.
The problem with this software was that it sometimes hanged and took all the CPU time.
Luckily, now this mechanism is handled by inotify in the linux kernel itself, so I could uninstall fam. :-)