Square One developed their own in-house software using
4th Dimension. More than 50 separate titles followed the creation of the Encyclopedia's database, and in 1997 Larkin sold Square One Books to American data company
Muze. In 2008, Larkin launched a new website whose original inspiration had come from the
All Time Top 1000 Albums, initially called 1000Greatest.com. This would later change its name to become the multi-media rating site and iPhone app, btoe.com (Best Things On Earth). Larkin closed down this website in August 2018 and re-directed the content to Musopedia.com. He was CEO and editor-in-chief of Musopedia Ltd. The company was dissolved in 2020. Larkin wrote the
liner notes for the
Rolling Stones' curated project ''Confessin' the Blues''. In November 2020, Larkin released his latest book,
Cover Me – The Vintage Art of Pan Books: 1950-1965. His first non-music book, it was a celebration of the classic
Pan Books paperbacks, incorporating full-colour reproductions of more than 300 of the original cover artworks. The book was nominated for the
H. R. F. Keating Award in 2021 and reached the shortlist final eight. A paperback edition was published in May 2022. ==Bibliography==