IFIP is sad to announces the death of Charles Lindsey, who was a British computer scientist known for his involvement with the programming language ALGOL 68. He was a member of IFIP WG2.1 (Algorithmic Languages and Calculi) until 2010 and was involved in support of the programming languages ALGOL 60 and ALGOL 68. He was awarded an IFIP Silver Core Award in 1977.

Lindsay was one of the editors of the Revised Report on Algol 68 and wrote the book:  An Informal Introduction to Algol 68. He was responsible for the research implementation of ALGOL 68 for the experimental MU5 computer at Manchester University and maintained an implementation of a subset named ALGOL 68S. He was also involved with developing international standards in programming and informatics. 

His webpage (https://www.clerew.man.ac.uk/) notes that he was also a member of the Computer Conservation Society (CCS), North-West Branch. He indicates that he had taken an active interest in Hartree’s Differential Analyser, a mechanical analogue machine built in 1936, part of which was on display in the Museum of Science and Industry in Manchester. In 1994, he did a survey of the machine with a view to having it restored to working order but was told that it was not Museum policy to restore it. In 2009 there was a change of policy, and he led a CCS working party to get it running in 2010. Unfortunately, the Museum then decided that they needed the space for something else and dismantled it. Undaunted, he worked on restoring a Meccano Differential Analyser made in 1947 by Nicholas Eyres (who had worked with Professor Hartree on the original machine during the war). 

Charles Lindsey was heavily involved in the IETF Working Group which produced the two standards RFC 5536 and RFC 5537 which provide the specification of how Usenet works, and in both of which he is listed as an author. He was also a member of the IETF DKIM Working Group which produced a scheme for signing headers of emails.

He wrote a number of papers, and books including:

    • Lindsey, C. H. (1996). A History of ALGOL 68. In Bergin, T. J.; Gibson, R. G. (eds.). History of Programming Languages-II. ACM Press. 
    • Lindsey, Charles H.; van der Meulen, S. G. (1977). An Informal Introduction to Algol 68. Amsterdam; Oxford: North-Holland Publishing.
    • Lindsey, Charles H. (1977). Structure charts a structured alternative to flowcharts. ACM SIGPLAN Notices 12(11).
  • Allbery, Russ and Lindsey, Charles H. (2009). Netnews Architecture and Protocols. RFC 5537: 1-48.
  • Lindsey, Charles H. (2013). Museums – What They Can and Should Be Doing. HC 2013: 258-265.

He will be remembered.