John the Ripper is a tool designed to help systems administrators to find weak (easy to guess or crack through brute force) passwords, and even automatically mail users warning them about it, if it is desired.

sysv-rc-conf provides a terminal GUI for managing "/etc/rc{runlevel}.d/" symlinks. The interface comes in two different flavors, one that simply allows turning services on or off and another that allows for more fine tuned management of the symlinks. Unlike most runlevel config programs, you can edit startup scripts for any runlevel, not just your current one.

OnionShare lets you securely and anonymously share a file of any size with someone. It works by starting a web server, making it accessible as a Tor hidden service, and generating an unguessable URL to access and download the file. It doesn't require setting up a server on the Internet somewhere or using a third party filesharing service. You host the file on your own computer and use a Tor hidden service to make it temporarily accessible over the Internet. The other user just needs to use the Tor Browser and TO Enter the URL to download the file from you.

ntopng is the next generation version of the original ntop, a network traffic probe that shows the network usage, similar to what the popular top Unix command does. ntop is based on libpcap and it has been written in a portable way in order to virtually run on every Unix platform, MacOSX and on Win32 as well.

Nagios is a host/service/network monitoring and management system.