bbwatch is a Perl- and Curses-based Big Brother monitoring tool. It features audible alerts, X background updating, acknowledgement of alerts, and direct tests and connections for broken services.
FileTraq was designed to be run periodically from the root crontab. Each time, it compares a list of system files with the copies that it keeps. Any changes are reported in diff or patchfile style, and dated backup copies are kept.
kimon is a simple ISDN monitor that attaches itself into the KDE taskbar. It displays the status of all connected ISDN devices that are known to ISDN4Linux.