Invited talk on multi-paradigm programming languages
Twenty Years After: Insights from the Oz Project - Peter Van Roy
Abstract: The Oz multi-paradigm language is now more than twenty years old. The first complete implementation, Mozart version 1.0, was released in 1999 and the CTM textbook was published by MIT Press in 2004. The history of Oz is explained in a paper that just appeared in HOPL IV (History of Programming Languages) in June 2020. Oz is both simple and powerful, yet it never really caught on. One of the reasons is its unusual syntax. Be that as it may, Oz had many good ideas and was far ahead of its time. Some ideas have made it to the mainstream and others are still waiting for their moment. In this talk, I will give some of the highlights of the Oz project with useful insights for programming and language design. In addition, I will explain Concurrency for Dummies, which is a form of functional programming where you can add threads at will without introducing bugs. I will also explain the best way to do general concurrent programming and the deep reason why a programming language needs to use nonfunctional concepts. It is a consequence of real-world specifications, which can force the language to support non-determinism or named state. I will show how to do logic programming in Oz and how to translate Prolog programs into Oz, including first-class interactive top levels, bagof, and cut (straightforward except for red cuts, which have no logical semantics). To make the talk more interactive, I encourage you take a look at the HOPL paper and think about what questions are most interesting for you. 

Bio: Peter Van Roy is professor in the ICTEAM Institute at the Université catholique de Louvain since 1996, where he heads the Programming Languages and Distributed Computing Research Group. He has an Engineering degree from the Vrije Universiteit Brussel (1983), a PhD in Computer Science from UC Berkeley (1990), and a Habilitation à Diriger des Recherches from the Université Paris Diderot (1996). He coordinated the European project SELFMAN on self management of large-scale systems and was partner in the projects MANCOOSI, EVERGROW, PEPITO, CoreGRID, and SyncFree. He is a developer of the Mozart Programming System and co-author of a well-known textbook on computer programming. He teaches two MOOCS on computer programming in the edX platform. He is currently coordinator of the Horizon 2020 
project LightKone (lightkone.eu), which is building lightweight application platforms for edge computing.