David Fisher is President of PolarSoft Inc., a Pittsburgh-based software company that specializes in BACnet® software development and consulting. He was a charter voting member of ASHRAE's SPC 135P and has been very active in the development and authoring of the BACnet® standard since its inception. Mr. Fisher has over 35 years of experience in real-time software, human-interface design, and distributed direct digital control systems, and holds several patents for laboratory control systems and fiber-optic communications. Mr. Fisher attended Carnegie Mellon University, where he studied computer science and artificial intelligence.