The Sylphis Generized Triangle Optimizer (SGTO) under the LGPL! The news are at the homepage of Sylphis3D developer network. This is an essential part of Sylphis3D as is allows
to automatically create low-poly simplified versions of high-poly meshes specialy for use with normal mapping.
The SGTO consists of a library (libsgto) that is the actual implementation of the optimizer and a command line utility that uses the library. The library is released under the Lesser GPL so that closed source projects can use it, the command line utility is release under the GPL.