This paper describes the GE Compliance Checker [GECCO], a knowledge-based application for use in the home mortgage industry. GECCO is a tool for automating the information-intensive processes of underwriting and reselling mortgage loans. GECCO was initially designed and deployed for one business component of GE Capital Mortgage Corporation [GECMC], and then successfully integrated into three other GECMC businesses. Its first application was for third-party underwriting. This was followed by the use of GECCO in wholesale pricing and registration, and in direct loan origination. Most recently, GECCO has evolved into a commercial product offered for purchase to mortgage lenders. GECCO has significantly improved the underwriting and resale process: quality control has become much more effective, adding consistency, completeness and robustness to the decision making process; the quantity of loans processed has increased; customer service has been enhanced; and a once subjective process has now been standardized. The successful use of AI has also permeated GECMC business application software to the extent that AI has become a requirement rather than a remote technology used in an isolated application.