Good portable z80 emulation library written in C

The free space simulation that lets you explore our universe in three dimensions

Binary logic gate simulator in C#

KSP is a game where the player creates and manages his own space program.

Build spacecraft, fly them, and try to help the Kerbals to fulfill their ultimate mission of conquering space.

The Fortius VR trainer is produced by a European company called Tacx. The Fortius unit goes far beyond simple magnetic or fluid resistance trainers by combining computer software with dynamic-resistance hardware to provide an experience that comes very close to a “real” outdoor ride.

VirtualBreadboard is a simulation and development environment for embedded applications that use microcontrollers. It is easy to use and can replace a protoboard for experimenting with new designs.

This program allows you to simulate simple circuits of logic gates on the screen. The gates and the "wires" connecting them are chosen from the toolbox of icons at the top of the page and then by clicking on the appropriate square on the grid itself.

Artemis is a multiplayer, multi-computer networked game for Windows computers.
Artemis simulates a spaceship bridge by networking several computers together. One computer runs the simulation and the "main screen", while the others serve as workstations for the normal jobs a bridge officer might do, like Helm, Communication, Engineering, and Weapon Control.

VertiSim is a 3-D simulation of the immortal Mattel toy from the 1970s, the Vertibird.

FreeTrack is a free optical motion tracking application for Microsoft Windows, released under the GNU General Public License. Its main function is inexpensive head tracking in computer games and simulations but can also be used for general computer accessibility, in particular hands-free computing.

Logisim is an educational tool for designing and simulating digital logic circuits.

ORBITER is a free flight simulator that goes beyond the confines of Earth's atmosphere. Launch the Space Shuttle from Kennedy Space Center to deploy a satellite, rendezvous with the International Space Station or take the futuristic Delta-glider for a tour through the solar system - the choice is yours.