OpenVBMS is a mature open-source "Google Earth"-like application for use in DIS-based distributed virtual simulation environment. It has seen extensive use in the industry, and recently, open-sourced.
RegMAS (Regional Multi Agent Simulator) is a spatially explicit multi-agent model framework, developed in C++ language and designed for long-term simulations of effects of government policies over agricultural systems (farm sizes, incomes, land use..).
This is a set of tools for for manipulating GPS Track Logs (".GPL") files generated by DeLorme's(tm) mapping products. It can also import data from ASCII and Cetus GPS. A command line Win NT/2K/9x interface exists and a GUI is in development.
Xconq is an engine for turn-based strategy games. Variety of game genres run under Xconq: historical, sci-fi, fantasy, and modern. AIs. Network games. Multiple UIs and platforms. Easy-to-learn game design language. Large games library available