OpenGL Eulerian fluid solver written in C++. This was my Masters' project and it was a tough challlenge. Overall, I could not bring the project to the level that I would have liked, but on the bright side I did learn many things about physically-based fluid simulation, which is a fascinating (and hard) subject. The solver is purely Eulerian, all the calculations happen on a staggered MAC grid and marker particles are used to track the fluid. This probably sounds like an easy task for those more versed in simulation or graphics programming in general, but it sucked a fair chunk of my commoner's soul during the 6-7 weeks of active development.
The primary source of documentation was Robert Bridson's "Fluid Simulation for Computer Graphics, Second Edition" (2015) [link], a book which I found to be both intimidating and extremely helpful.