Kellner is taking on the role of non-executive chairman of the board and remains a significant shareholder in the company.
French most recently served as chief operating officer of Intergraph Corporation, a global company specializing in geospatial and computer-aided design software. Intergraph has 4,000 employees in more than 50 countries.
More than 130,000 users in 11,000 agencies use Applied Systems software.