AVFS (A Virtual File System) is an easy-to-install system that enables all programs to access archived, compressed, remote, or other kind of virtual files without the need to recompile programs or the kernel. The following modules are currently implemented: tar, zip, rar, gzip, bzip2, ftp, http, dav, rsh/ssh, floppy, and many more.
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.
BleachBit deletes junk to recover disk space and maintain privacy. It rids your system of old junk including cache, Internet history, temporary files, unused locale files (better than localepurge), logs, and cookies. Designed for Linux systems, it wipes clean 50 applications including Adobe Reader, Bash, Firefox, Flash, OpenOffice.org, Opera, Real Player, Skype, and more. It shreds files so that they cannot be recovered, and it wipes free disk space to hide insecurely deleted files. It offers both a simple PyGTK GUI and a command line interface for automation.