Allen joined X/Open Company Limited in 1993 as Chief Financial Officer and Vice President of Business Development. He relinquished his role as CFO in order to focus on developing the company's testing and branding operations, leading its efforts in licensing the UNIX trademark to suppliers. After the merger between OSF and X/Open that formed The Open Group, he was responsible for combining the membership activities of the two companies.

Allen Brown has more than 24 years of experience in the computer industry. Before joining The Open Group, he worked as a consultant, specializing in start-up and turn-around companies. His duties included the provision of  financial management services, and implementation of the IT systems and solutions necessary to integrate financial management with business activity.

Allen previously spent 13 years with the Anglo-Dutch blue chip conglomerate Unilever plc, in a number of line management finance positions. For over eight years this included looking after the commercial aspects of its computer bureau services and its manufacture and marketing of hand-held portable data capture devices.