UnusedPkg is a diagnostic tool to search the oldest unused packages in your Linux system. UnusedPkg prints a sorted list with the size and number of days that a package has been idle. This helps you determine what packages can be manually removed to clean the system. It supports any apt-based distribution (tested on Debian and Ubuntu) and Slackware.
SimMon is a cross platform monitoring tool which runs on almost any OS that supports the Java Virtual Machine 1.4+. Monitoring is done through the execution of existing monitoring scripts (Perl/VBS) or existing shell commands. Currently monitoring scripts are available for Solaris, Linux, Mac OS X, and Windows based systems. Network devices can be monitored via the integrated SNMPv1 scheduler.
scanmem is a simple interactive debugging utility for Linux that can be used to locate the address of a variable in an executing program. scanmem can then be used to modify the variable once, or continually over a period of time. It is similar to the "pokefinders" used to cheat at video games.
iogen is an I/O generator. It forks child processes that each run a mix of reads and writes. The idea is to generate heavily fragmented files to make the hardware suffer as much as possible. This tool has been used to test filesystems, drivers, firmware, and hardware devices. It is by no means meant as a performance measuring tool since it tries to recreate the worst case scenario I/O.
weedit is a file duplicate scanner with database support. It uses CRC32, MD5, and file size to scan for duplicates. Files that are deleted are automatically removed from the database when a duplicate is found. It will only rescan files if the creation time or last write time change. It will only delete duplicated files if the parameter for deleting is used. The default setting is to report only.