The Powder toy is coded in c++ and sdl, that is not Java like powder game. Java can be used in web pages, exe applications not.
Edit from the farther future of 29 sept 2012:
"The Powder Toy is coded in C with the SDL library, the new TPT++ is coded in C++. Java applets can easily be used in web pages, but they are tons slower."
@bybyty56(View Post) We know. I mentioned it in my reply, for example. Powder Game lacks in functionality and speed what TPT prospers in. TPT is written in a lower-level programming language that is translated to machine code, which for safety reasons can not be run online.