An awesome list of resources to design, implement and operate computer networks.
skies-adsb is a virtual plane spotting progressive web app / virtual aquarium (with aircraft instead of fish) / interactive real-time simulation. Aircraft are tracked via unfiltered ADS-B transponder data in real-time and rendered in 3D. The ADS-B data source is meant to be a RTL-SDR receiver connected to a Raspberry Pi running on your home network. Flight status data is provided by the FlightAware AeroAPI v2. The aircraft photos are provided by Planespotters.net.
a tool for thinking in systems
A nifty artificial life simulation for *nix in which you write parameters for virtual critters (kind of like core wars) which then populate an environment. Over time, the parameters of your critters evolve so that they can better survive in the playing field.
A suite of open source electronic design tools. Uses a GUI for schematic capture. Also capable of analog and digital simulation, generation of parts lists and export of PCB designs for fabrication.
A point-in-time simulation of the position of the planets in the solar system, based upon date and time. Also calculates the ephemera for the planets at that point in time.
A free, open source mathematical processing system written in Python.
Introduced at The Last HOPE, this online project is a recreation of yesteryear using open source software. Phiber Optik used a modified build of Asterisk to build a virtual telephone network that you can hack around with using a blue box (or a software emulation thereof). It's completely isolated and completely legal, and was built for those of us who got into phreaking after electromechanical switching disappeared. If you want, you can set your own instance up by downloading the patches for the software.
Lifewiki is /the/ wiki to visit if you're interested in Conway's Game of Life in particular, or cellular automata in general. You can get lost here for weeks, so take your time.