Java Marine API is an NMEA 0183 library for Java.
For furher info and latest source code, see project's Github pages.
http://github.com/ktuukkan/marine-api/
This project hosts various plugins for the OpenCPN chart plotter, which are not bundled with the core package.
OpenCPN is a free software (GPLv2) project to create a concise chart plotter and navigation software, for use underway or as a planning tool. OpenCPN is developed by a team of active sailors using real world conditions for program testing and refinement.
GNU AIS is software for demodulating and decoding Automatic Identification System messages used by ships to navigate. You will need a VHF receiver with discriminator output to get it to work.
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