debcheckroot is a tool that retrieves file checksums online or from read only media. It provides trusted verification of your root file system at least as far as you can trust your Internet connection or your verification medium (DVD, BD, etc.). Unlike debsums, it doesn't rely on locally stored md5sums which can be modified by an attacker along with the files themselves. It also provides cleaner and better structured output, and can spot files added to your system by someone else.
Many times, developers (or even, normal users) run into an issue of searching for a resource that is inside a zip. Worse, sometime the resource is inside a zip that is itself inside another zip (i.e. a nested archive). zfind solves this problem. It is very fast and works on most common archive/compress files. It support full name search as well as regular expression search. Apart from command line usage, it also provides API support that lets you use it in your Java code as a 3rd party library.