Space Simulation Toolkit A physics sandbox on your GPU

Everything here is built from atoms, and atoms can link up into structures. Change their properties and the same particles become gas, liquid, soft jelly or solid rock, with heat, energy and chemical processes in the mix. The trick is that the physics is calculated on your graphics card, so hundreds of thousands of particles can move at once without the whole thing grinding to a halt. Drop a rock and it tumbles; build a brick wall and it stays put while everything else crashes into it. The more powerful the card, the bigger the worlds you can throw around. It is a falling-sand toy grown into something enormous.

Beyond plain physics, the toolkit lets you set up A-Life worlds and experiment with evolution and AI. The built-in example is Protobiome: a small living world with light, water and soil, where plants grow and creatures wander under evolutionary genetics. Nothing is scripted; the beings that thrive are the ones whose traits happen to work. You can also design your own mechanisms and materials, adjust the laws of physics themselves, and see what survives your tinkering. It rewards patience and curiosity more than quick fingers, and the results are yours alone: no two experiments play out the same way.