* Are you aware that FPC has a matrix unit?
Now I am

* Do you think it suits the needs of games?
Another problem I see is the compatibility with 3D apis, OpenGL in my case . Is the column/row ordering same as in OpenGL. Is there an easy way of sending and retrievng matrices to and from OpenGL and so on. Although a good, optimised 3D math library shipped with a compiler is a nice thing to have.
* If you implemented one yourself, why did you do so?
Generaly I prefer to write my own code then made by others. I know that often it is reinventing the wheel, but it is a learning experience and it is easier to fit my own code into my projects.