Advisory Check is a program that reads security advisories for you. It gathers security advisories using RSS, RDF, or XML feeds, compares them against the installed software, and alerts you if you're vulnerable. A wide variety of package managers can be queried to detect installed software. Remote systems can be monitored by using the integrated SSH, Windows-RPC, and Nmap support.
Diskus is a high-level hard drive diagnostic and limited repair tool. It checks the disk geometry by writing numbered IDs into the sectors of the hard drive. Later one can verify that these sector-IDs on the disk are still correct, thereby detecting data which was not correctly written. There is an option to "freshen" the data on your harddrive, which will read and rewrite the sectors. With modern drives this will re-map defective sectors.
EsteidUtil is a wxWidgets GUI tool for managing the Estonian ID smartcard. It allows the user to see the data on th card, change PINs, and perform some basic diagnostics both on card and necessary opsys configuration. The code has useful low-dependency C++ classes for other kinds of smartcard handling.
FSHeal aims to be a general filesystem tool that can scan and report vital "defective" information about the filesystem like broken symlinks, forgotten backup files, and left-over object files, but also source files, documentation files, user documents, and so on. It will scan the filesystem without modifying anything and reporting all the data to a logfile specified by the user which can then be reviewed and actions taken accordingly.
FTPL (FakeTime Preload Library, aka libfaketime) intercepts various system library calls and tricks programs of your choice into seeing a faked system time without having to change the time system-wide. This can be used for running legacy software with Y2K bugs, testing software for year-2038 compliance, debugging time-related issues such as expired SSL certificates, and using software that ceases to run outside a certain time frame. The faked time can be specified either absolutely or relative to the real current time, and optionally also affects file timestamps. The faked clock continues to run, but can optionally be frozen, slowed down, or made faster. A wrapper script "faketime" simplifies the usage, similar to tools such as fakechroot.
INSERT (the Inside Security Rescue Toolkit) aims to be a multi-functional, multi-purpose disaster recovery and network analysis system. It boots from a credit card-sized CD-ROM and is basically a stripped-down version of Knoppix. It features good hardware detection, fluxbox, emelfm, links-hacked, ssh, tcpdump, nmap, chntpwd, and much more. It provides full read-write support for NTFS partitions (using ntfs-3g), and the ClamAV virus scanner (including a fairly recent signature database and a GUI). It provides partition handling with gParted and also has a network boot facility.