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.
Hot Copy creates an instant point-in-time snapshot of any block device while the system is running without interrupting applications or requiring the use of LVM. As block level changes are made to the real device, hot copy makes a backup copy of the changed block. The changed blocks are efficiently stored in unused space on your hard disk. These stored changed blocks maintain a point-in-time snapshot and space is only needed when you make changes to the real device. You can even write to your snapshots.
fsarchiver is a system tool that allows you to save the contents of a filesystem to a compressed archive file. The filesystem can be restored on a partition that has a different size, and it can be restored on a different filesystem. Unlike tar/dar, fsarchiver also creates the filesystem when it extracts the data to partitions. Everything is checksummed in the archive in order to protect the data. If the archive is corrupt, you just lose the current file, not the whole archive.
iloog is a Gentoo-based live CD targeted mainly at students and scientists. It features UnionFS filesystem support that enables you to write everywhere on the LiveCD and install extra packages, a graphical X environment through the Fluxbox window manager, many programming editors and IDEs, and a plethora of scientific applications, including Octave, Namd, Merlin, and full (La)TeX support.
Chiron FS is a FUSE based filesystem that implements replication at the filesystem level like RAID 1 does at the device level. The replicated filesystem may be of any kind you want; the only requisite is that you mount it. There is no need for special configuration files; the setup is as simple as one mount command (or one line in fstab).
giis (gET iT i sAY) is a file recovery tool for Ext2/Ext3 filesystems. Once installed, current files and newly created files can be recovered. It allows users to recover all deleted files, recover files owned by a specific user, dump data from old file locations, and recover files of a specific type, such as text or PNG. A forensic analyzer is also provided to assist users during recovery.
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.