Mr. Paul, a lawyer-businessman, and Mrs. Judi Paul, a homemaker with a degree in elementary education, though she never taught school, began their software business, Advantage Learning Systems, in 1986 from the basement of their home in Port Edwards, Wis. They sold it 25 years later for a reported $455 million. The Pauls’ most popular program, Accelerated Reader, like their other programs for math and vocabulary-building, was lauded in company advertising for its ability to raise scores on such tests. He received his bachelor’s degree in economics from the University of Illinois, a master’s of business administration from Bradley University in Peoria, and a law degree from the University of Illinois College of Law. He held positions at the Caterpillar Tractor Company in Peoria before joining Best Power Technology, a developer of computer backup systems for businesses, where he was chief executive until the company was sold in 1994. By then, the company that he and Judi Paul founded was in full swing. Mr. Paul became chief executive and chairman when it went public in 1997 and remained involved in operations until he and his wife sold the company and moved to Boulder in 2011. Today it employs about 1,000 people at its offices in Wisconsin Rapids. Besides his wife, Mr. Paul is survived by a son, Alexander, and three daughters, Bliss Cohen, Alyssa Maria and Mia Moe, as well as 13 grandchildren.