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.
OpenClass is a simple solution for class control. It provides multicast screen projection (sending the teacher's screen to all of the students), student attention requests (blocking student activities and asking them to look at teacher), viewing of all student screens at once, direct messaging to students, file and URL sharing, computer shutdown, access control for specific classes, and support for multi-seat configurations and multiple clients per machine. For students it provides automatic teacher discovery via broadcast, "raise hand" functionality, and automatic handling of network saturation and disconnection events.