syfluid
Fancy interactive fluid simulation for gfx fans, VJs and demo coders
...Drag while your left mouse button is pressed to make the whole thing move, i.e. to "draw" the "forces" that you're adding to the fluid/density field. Press "r" to clear the screen and "m" to open the menu. Press "1" .. "8" to switch color presets. SPACE to pause. "s" to save a png or jpg.
syfluid is written in C++ using OpenGL. Even though it is heavily performance optimized and using OpenGL Shading Language (GLSL), it is a performance hog. Use "f" to show the FPS. If they are lower than 30, then reduce the quality parameter that you find in the menu from 200 to e.g. 100. ...