and Richard G. Gibson (Addison Wesley, 1996). HOPL III 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. As with HOPL I and HOPL II, the papers were managed with a multiple stage review/revision process. The HOPL III programming languages can be broadly categorized into five classes (or paradigms): Object-Oriented (Modula-2, Oberon, C++, Self, Emerald, and BETA), Functional (Haskell), Scripting (AppleScript, Lua), Reactive (Erlang, StateCharts), and Parallel (ZPL, High Performance Fortran). Each HOPL III paper describes the perspective of the creators of the language. HOPL IV HOPL IV was to be held June 14–16, 2020 in London, United Kingdom, but was postponed to 2021 due to the COVID-19 pandemic. The conference co-chairs were Guy L. Steele Jr. and Richard P. Gabriel. The languages covered in this conference had to be widely adopted by 2011. References Further reading External links Official HOPL III conference website Official HOPL IV conference website HOPL: an interactive Roster of Programming Languages History of Programming Languages Conference Records 1972-1993. Charles Babbage Institute, University of Minnesota, Minneapolis. A history of the history of programming languages by Thomas J. (Tim) Bergin Association for Computing Machinery conferences Computer science conferences History of software Programming languages conferences