These are C++ templates for matrices. Use free of charge for any purposes, including commercial use.
The main header you should include into your projects is MyMatrices.h. Other headers should be just lying near it because it includes them internally. Feel free to modify the headers as you like and use them for any purpose whatsoever.
MatrixF and MatrixD are float and double matrices respectively. You have to specify their dimension at construction time. e.g. MatrixF m(10, 10);