Actionscript physics engine which supports particles attracting eachother

I'm looking for a physics engine for Actionscript which supports particles attracting eachother. Like in this example.

So not just objects being attracted by the floor like in most engines 开发者_开发知识库(eg. APE afaik doesn't support particles attracting eachother)

Here are a couple to add to the list:

Fisix Engine

Flade - I don't know if it has the attractor portion but it's still pretty cool. :)

Check out the Hype framework. There's loads of attractor, particles, followers, et al. I think you may find something you like regardless ;)

The 2 most famous physics engines for flash are:

1. box2d (http://box2dflash.sourceforge.net/)
2. Nape (http://napephys.com/)

make sure to check them out.