Mr. Gilbert H. Castle is the founder of Castle Consulting. He has been a GIS consultant since 1978. Prior to starting Castle Consulting, he was a Regional Director of the real estate consulting division of Deloitte & Touche. Mr. Castle is a Past President of the Urban and Regional Information Systems Association, North America's largest and oldest professional society for GIS practitioners. He has more than 150 publications and conference presentations to his credit, primarily on applied computer technology in land use decisions. For example, he is responsible for two seminal books – GIS in Real Estate (1998) and Profiting from a Geographic Information System (1994). For several years he also wrote the real estate column for Business Geographics magazine. Mr. Castle has lectured at numerous universities on applied GIS technology, including the Massachusetts Institute of Technology, the University of Pennsylvania, Stanford University, the University of California at Berkeley, Texas Tech, and Georgia Tech. He holds a Bachelor of Science degree in Economics, Cum Laude, from Harvard University, and a Master of City Planning degree from the University of Pennsylvania.

Castle Consulting (U.S.) was the first company in the world to focus primarily on Geographic Information Systems (GIS) applications in the real estate industry. As an unabashed champion of the benefits of GIS technology, Castle Consulting throughout its history has balanced – in equal measure – consulting engagements, customized system development projects, and educational activities. Clients have come from all levels of the organization, including C-level executives.


In recent years attention has shifted to India. Not only is the Subcontinent arguably the most rapidly expanding economy in the world, but also is on the verge of having the largest and most sophisticated cadre of GIS professionals on the planet. (If Horace Greeley were alive today, his advice would most likely be “Go east, young man!”) Accordingly, Castle Consulting India was founded in 2009 to provide the GIS-related products and services described at this Web site, for clients in India, the United States, and the rest of the world.