Ceph is a distributed network file system designed to provide excellent performance, reliability, and scalability (from terabytes to exabytes). Data is stored in the form of "objects" (variable length, named chunks of data) in a distributed and fault tolerant cluster of OSDs (object storage devices--servers running the Ceph OSD daemon). Metadata (the file system namespace) is managed by an independent cluster of metadata servers (MDSs), which dynamically repartitions the directory hierarchy in response to the current workload.
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.
EncFS is an encrypted pass-through filesystem which runs in userspace on Linux (using the FUSE kernel module). Similar in design to CFS and other pass-through filesystems, all data is encrypted and stored in the underlying filesystem. Unlike loopback filesystems, there is no predetermined or pre-allocated filesystem size.
FAM, the File Alteration Monitor, provides an API which applications can use to be notified when specific files or directories are changed. It comes in two parts: fam, the daemon which listens for requests and delivers notification, and libfam, a library which client applications can use to communicate with fam.
KDirStat (KDE Directory Statistics) is a small utility program that sums up disk usage for direcory trees, very much like the Unix 'du' command. It displays the disk space used up by a directory tree, both numerically and graphically. It is network transparent (i.e., you can use it to sum up FTP servers), and comes with predefined and user configurable cleanup actions. You can directly open a directory branch in Konqueror or the shell of your choice, compress it to a .tar.bz2 archive, or define your own cleanup actions.