In the early 1980s, Muller co-founded the business software company
Sage Group along with
David Goldman and
Graham Wylie in
Newcastle upon Tyne, England while he was a computer science lecturer at Newcastle University. Muller left Sage in late 1985 following a dispute with fellow shareholders and took legal action against them and the company in the following years. After leaving Sage Muller returned to the United States. In later life Muller lived in
Mae Sot, Thailand and became an author of fiction novels having three books published by Club Lighthouse in 2012;
Suicide Inc.,
Flight of the Marbles and
The Circle of Ouroboros. He also co-founded the Aarau Literary Agency in 2001. == Death ==