ZeroTier One creates virtual Ethernet networks of almost unlimited size.
Flatland is a simple and easy to use command line utility for plotting points in n-dimensional spaces. It was inspired by Quickplot and can handle very large numbers of points and very large numbers of dimensions. It is released under the GPL.
EGADS stands for Evolutionary Gaussian Automatic Decomposition System and is a little GPLed project that uses evolutionary computation to decompose complex curves composed of multiple normally-distributed populations into their constituent parts. It is released under the GPL.
This project is now defunct. I might post the source code as open source at some point.
FilePhile is a utility for person-to-person file transfers. The base client is
free, and I'm currently working on some enterprise applications. The current version is in Java, but there's a possibility
that the next major revision will be native and based on libFireDoor if that ever comes out of vaporware mode. Before that, a
pro version will probably come along for enterprise users.
Here's an implementation of the Mersenne Twister random number generator for the specialized processing units on the Cell Broadband Engine chip. Feel free to use it, since it's based on the original MT code and so is under the same (basically PD) license.
Nanopond (click to read more) is a very tiny, simple, and fast virtual CPU based artificial life system. It's been used by a few universities to demonstration evolutionary computation, artificial life, or simply to show what a virtual machine is. Its goal was to show how simple digital artificial life can be and to have a system small enough to fit in a programmers' head. It's written in C.