John W. Eaton
I'm the original author and primary maintainer of GNU Octave, a full-featured interactive system for numerical computations with hundreds of thousands of users worldwide. I currently work to improve Octave and coordinate the activities of the increasingly active and diverse group of volunteers developing Octave.
The best way to reach me is by email.
Unless you are inquiring about commercial support services, please send all Octave related mail to one of the Octave mailing lists.
If you like what I've done with Octave, feel free to throw money at me.