Includes free (MIT) code to load its save format (pfx). It also exports particle systems as Lua code + PNG if you prefer that. Example code that shows how to load particle systems is included, both for saved and exported particle systems.
Quick usage tip: Clicking and dragging left/right on number edit controls (those with the triangles on the sides) quickly changes their value. You can also click on numbers and edit them manually.
I'm sorry for the shitty color picker. I hate it too.
Runs on Windows + Linux, 32 or 64 bit OS.

