It is my pleasure to invite submissions to the OCaml Users and Developers Workshop 2021, which is again co-located with ICFP and will be held virtually this year. The OCaml Users and Developers Workshop brings together industrial users of OCaml with academics and hackers who are working on extending the language, type system, and tools. Previous editions have been co-located with ICFP 2012 in Copenhagen, ICFP 2013 in Boston, ICFP 2014 in Gothenburg, ICFP 2015 in Vancouver, ICFP 2016 in Nara, ICFP 2017 in Oxford, ICFP 2018 in St Louis, ICFP 2019 in Berlin, and was virtual for ICFP 2020, following the OCaml Meetings in Paris in 2010 and 2011. Please note that the deadline for abstract submission is set on May 20, a week from now. Don't wait to start preparing your submission :-). ## Important Links - workshop site: https://icfp21.sigplan.org/home/ocaml-2021 - submission site: https://ocaml2021.hotcrp.com ## Important dates * Thursday 20th May (any time zone): Abstract submission deadline * Friday 18th July: Author notification * Friday 27th August: OCaml Workshop ## Scope Presentations and discussions focus on the OCaml programming language and its community. We aim to solicit talks on all aspects related to improving the use or development of the language and its programming environment, including, for example (but not limited to): * compiler developments, new backends, runtime and architectures * practical type system improvements, such as GADTs, first-class modules, generic programming, or dependent types * new library or application releases, and their design rationales * tools and infrastructure services, and their enhancements * prominent industrial or experimental uses of OCaml, or deployments in unusual situations. ## Presentations Presentations will be held in the online format. Each presentation comprise a prerecorded presentation and an interactive live Q&A session after the talk. Each talk will be re-translated three times in different time zones. Session chairs and volunteers will assist the authors in preparing and casting the presentation. Each presentation will be made available through the ocaml.org website. ## Submission To submit a presentation, please register a description of the talk (about 2 pages long) at https://ocaml2021.hotcrp.com/ providing a clear statement of what will be provided by the presentation: the problems that are addressed, the solutions or methods that are proposed. LaTeX-produced PDFs are a common and welcome submission format. For accessibility purposes, we ask PDF submitters to also provide the sources of their submission in a textual format, such as .tex sources. Reviewers may read either the submitted PDF or the text version. ## Camera ready presentations A pre-recorded versions of accepted presentation shall be provided before August, 13th. Volunteers will provide technical assistance to authors as well as provide necessary feedback and ensure that all videos match our quality standards. ## ML family workshop The ML family workshop, held on the previous day, deals with general issues of the ML-style programming and type systems, focuses on more research-oriented work that is less specific to a language in particular. There is an overlap between the two workshops, and we have occasionally transferred presentations from one to the other in the past. Authors who feel their submission fits both workshops are encouraged to mention it at submission time and/or contact the Program Chairs. ## Program Commitee Frédéric Bour, Tarides, France Cristina Rosu, Janestreet, UK Hakjoo Oh, Korea University, Korea Hugo Heuzard, France Jeffrey A. Scofield, Formalsim, USA Jonathan Protzenko, MSR, USA Joris Giovanangeli, Ahrefs, Singapore Jun Furuse, Dailambda, Japan Kihong Heo, KAIST, Korea Kate Deplaix, OCaml Labs, UK Mehdi Bouaziz, Nomadic Labs, France Simon Castellan, INRIA, France Ryohei Tokuda, Idein, Japan Vaivaswatha Nagaraj, Zilliqa, India Youyou Cong, Tokyo Institute of Technology, Japan