Wocvim is a WoC client for Vim. WoC is a protocol which enables the use of hyperlinks in plain ASCII texts. The links can point to local or remote locations. The protocol is specifically designed to support source code, but it can be used in any text. For source code, it's also possible to use ad-hoc tag generators like cscope and ctags.
EPOR is an extensible package organiser for Unix-like systems. It's written to trace filesystem changes (something being installed) and save this information in a simple text database (this, as any other provided feature, is customisable via the embedded Guile interpreter). Database entries contain information supplied by the command line (package name, version, etc.) and traced by filesystem changes (new directories, files, etc.). This is achieved using the "LD_PRELOAD method''.