lostamd5found (pronounced "lost and md5-found") uses the md5sum database of rpm or dpkg to find the original location of files which have lost their names and ended up in /lost+found. Of course, this only works for unmodified files which are part of the original packages of your system.
fsck for most Linux filesystems will place recovered files in a "lost+found" directory, including ext2, ext3 and reiserfs. If you have suffered a Linux disk disaster of one sort or another, you may have recovered a fair amount of data with fsck. If you can send the system files back to where they belong, using lostamd5found, you may be able to get your system running, and perhaps find your real data among the system files.
Perhaps the most significant feat of this software is that it demonstrates that there is a useful application for the join command.
Audience: Linux users with less than stable hardware platforms
System requirements: bash, gnu textutils
Source license: GPL
Download and documentation