6jack is a framework for testing, analyzing, and fuzzing network applications. 6jack runs a command, intercepts calls to common network-related system calls, and passes them through an external filter. A filter can be written in any language supporting the MessagePack serialization library. 6jack is especially useful for writing tests for clients and servers, debugging and reverse engineering protocols, sketching filtering proxies, and fuzzing.
GeoToad is a geocaching query tool to help speed up the boring part of geocaching: choosing the cache and collecting the data. It allows you to generate any kind of complex query you want, and the program will go and poll the Geocaching query, grab the data, and output it to any format you want. The Geocache info can be synced straight to your GPS, iPod, PDA, or cell phone in over 20 different formats.