ThreadedNewton is provided under the zlib/libpng license.  See license.txt for details.

You'll need Newton from http://physicsengine.com/

copy libnewton32.a and Newton.h into the Newton folder to build.  Remember to ranlib libnewton32.a

Contact Keith Bauer (OneSadCookie@gmail.com) with suggestions, bug 
reports, &c.