HOPL III was held June 9–10, 2007 in San Diego, California. Brent Hailpern and Barbara G. Ryder were the Conference co-Chairs. HOPL III had an open call for participation and asked for papers on either the early history or the evolution of programming languages. The languages must have come into existence before 1996 and been widely used since 1998, either commercially or within a specific domain. Research languages that had a great influence on subsequent programming languages were also candidates for submission.