Mark has many years of experience in developing design and modeling software. He was one of the founders of AtLast Software, the makers of SketchUp, which was acquired by Google. He was a user interaction designer and was the windows product manager through SketchUp Version 4.0. He was a principal in Lunar Graphics who developed the Realize Rendering Tool. He also designed and programmed the Cadman Architectural Drafting System and the Cadman Layer Manager, both add on programs for AutoCAD software.