Even better in 3D: http://david.li/fluid/

I like this version more (also david.li): http://www.adultswim.com/etcetera/soup/ (2D, but funnier)

The performance of this on my laptop invariably blows my mind

Ohhh old school, FLIP was fun! David should upgrade to APIC.

This project is 3-4 years old and the last commit was 2 years ago.

By comparison Box2D is actively maintained: https://github.com/erincatto/Box2D/commits/master

This is the problem when you fork a project. :/

Ok, we'll split the difference and call it 2014.

For anyone who wants to get their feet wet just a little (pun not intended). https://www.khanacademy.org/partner-content/pixar/simulation. Also recommend checking out the entire series.

Nice. Is there anything like this for simulating gas? I want to make a 2D simulation of an internal combustion engine.

perhaps not quite what you want, but you can do this with box2d: https://www.youtube.com/watch?v=8kZRpouZ3OQ

I can't wait til this sort of thing is common in 3D.

It's brutally expensive, unfortunately. Moving from 2D to 3D you go from needing O(n²) particles to O(n³) particles to fill a box. That's an awful increase in complexity, and it really limits the size of what you can do.

With that said, NVIDIA has a boatload of money, top-notch hardware skills and fluid simulation experts like Matthias Müller-Fischer working on the problem. NVIDIA Flex[1] is amazing to behold.

[1]: https://youtu.be/pfonMfP__Ks

As a slight aside, is NVIDIA's motivation profit from the gaming industry or does this find industrial application outside of the obvious visual presentations?

Possibly, given that - besides all that recent neural-networks-on-GPU craze - people run e.g. CFD simulations on GPUs. I recall SpaceX in particular doing simulations for their rockets on NVIDIA hardware.

https://blogs.nvidia.com/blog/2015/03/17/mars-rocket/

Flex, PhysX and Gameworks are all meant for games, but I would suspect that the game physics talent helped guide CUDA, which does have a lot of industrial applications.

They aquired Müller and PhysX when they bought Ageia in 2008. They changed Ageia's direction away from developing dedicated hardware (a Physics Processing Unit) to instead leverage the GPU for physics calculations.