BRL-CAD is a powerful cross-platform constructive solid geometry solid modeling system that includes an interactive geometry editor, ray-tracing for rendering & geometric analyses, network distributed framebuffer support, image & signal-processing tools.
A library that makes writing parallel (multithreaded) for loops in Java 5+ easier. It also supports parallel processing of lists and arrays, asynchronous invocation, progress and completion notification, computation interruption and results merging.
Generic packet visualization tool for generating flow diagrams from formatted logs. Can be used for cache coherency diagrams, software interaction diagrams or to plot network communications.