FlightGear - The FlightGear flight simulator project is an open-source, multi-platform, cooperative flight simulator development project. It also simulates space flight in Earth's orbit. It's flight dynamics engine (JSBSim) is used in a 2015 NASA benchmark.
GeoFS - Free, Web based flight simulator with worldwide satellite images.
X-Plane - The world's most advanced flight simulator just got an upgrade. Download the free demo today for Windows, macOS, & Linux.
esports for engineers - An award-winning strategy game for each day of the week, with daily and cumulative weekly score to help you improve. Games include classic flight and racing sims, deep learning Chess and Go, Contract Bridge. Sims take place in historical settings.
NinjaOne - NinjaOne (Formerly NinjaRMM) provides remote monitoring and management software that combines powerful functionality with a fast, modern UI. Easily remediate IT issues, automate common tasks, and support end-users with powerful IT management tools.
YS Flight Simulator - YS Flight Simulator is a free flight simulator specifically for slow computers.