sodaplay.com
It's pretty fun, you use different mass types to make joints, use spring motions to do stuff, define gravity and more. Great for making fun little models or toys in 3D on the web.

You can create an account 100% free, and save as many models as you want. You can even see AND save other peoples' models in your files, if you want to tinker with it or even just keep it cause you really liked it.

It'll take a while to learn how to make more advanced movements in models, but it's fairly simple. I'm still making silly things like balls on sticks and stickmen poking each other with swords.

Anyway, you guys should check it out. It's really fun.

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*chews on jes's sig* *** jools changed topic to "AND LIKED IT!"