MySQLTuner is a script written in Perl that will assist you with your MySQL configuration and make recommendations for increased performance and stability.

a tool for backing up your data using rsync (if you want to get help, use https://lists.sourceforge.net/lists/listinfo/rsnapshot-discuss)

ddclient updates dynamic DNS entries for accounts on a wide range of dynamic DNS services.

Authentication, authorization, traceability and auditability for SSH accesses.

Monitorix is a free, open source, lightweight system monitoring tool.

Pulled Pork for Snort and Suricata rule management (from Google code)

PHP basic ressource profiler (CPU/memory), safe and useful for production sites

Log colorizer perl script

Monitoring Plugins by William Leibzon

Hak5 episodes links and little scripts that help download episodes.