History of Programming Languages (HOPL) is an ACM SIGPLAN conference held approximately every 14 years. HOPL IV was scheduled for this month, and Morten Kromberg and Roger Hui were invited to contribute. Unfortunately, like so many other conferences this year, it has had to be postponed for 12 months, but the papers (including Morten and Roger’s “APL Since 1978”) are available to download from https://dl.acm.org/toc/pacmpl/2020/4/HOPL (currently free of charge).
