fam++ is a C++ wrapper for fam, which uses imon or DNotify (Linux 2.4.x) to inform it when inodes change (the net effect being that applications can register interest in a file, and have events send to the application when the file changes). Fam++ also integrates with gdk and Loki to make creation of C++ GTK+/GNOME apps simpler.
v9fs provides a Plan 9 9P2000 resource sharing protocol for the Linux 2.6 kernel. This can be used to share files, devices, /proc, /sys, etc. It also works with Plan 9 file servers, and can be used to mount synthetic file systems from Plan 9 applications (see the plan9port project).
DFF (Digital Forensics Framework) is a simple but powerful tool with a flexible module system which will help you in your digital forensics works, including file recovery due to error or crash, evidence research and analysis, etc. DFF provides a robust architecture and some handy modules.
Partition Image is a Linux/UNIX utility similar to Symantec's Ghost. This uility saves partitions in the EXT2, Reiserfs, NTFS, HPFS, FAT16, and FAT32 file system formats to an image file. The image file can be compressed with gzip or bzip2 in order to save disk space, and it can be split in order to fit onto a series of floppy disks. This program can be useful for backup purposes. A boot/root disk is also provided, allowing you to run Partition Image without Linux installed on the hard disk.
anyfs-tools allows you to recover and convert filesystems while using minimal extra disk space. Unlike other recovery tools, anyfs-tools doesn't copy all the files found on other disks (or partitions), but only saves information about the location of the file blocks to an external inode table. After recovery, a user may mount the damaged filesystem with anyfs and the external inode table and then interact with all recovered files with any program.