OCaml Users and Developers Workshop 2025

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, ICFP 2020 virtually, ICFP 2021 virtually, ICFP 2022 in Ljubljana, ICFP 2023 in Seattle, and ICFP 2024 in Milan.

OCaml 2025 will be held on October 17th, 2025, in Singapore. It will be a hybrid event with the same streaming modalities as OCaml 2024, allowing people to attend and even give talks remotely.

Call for Presentations

We are currently accepting talk proposal submissions for OCaml 2025. The submission deadline is Thursday, July 3rd (any timezone).

Scope

Presentations and discussions focus on the OCaml programming language as well as the OCaml ecosystem and its community. We aim to solicit talks on all aspects and perspectives related to improving the use or development of the language and its programming environment.

Different aspects include, for example (but are 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, tool 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.

Different perspectives include, for example (but are not limited to):

• scientific and/or research-oriented
• engineering and/or user-oriented
• social and/or community-oriented.

Presentations

The workshop is an informal meeting with no formal proceedings. The presentation material will be available online from the workshop homepage. The presentations may be recorded and made available at a later date.

The main presentation format is a workshop talk, traditionally around 20 minutes in length, plus question time, but we might also have a poster session during the workshop – this allows to present more diverse work, and gives time for discussion. The program committee will decide which presentations should be delivered as posters or talks.

Submission

The submission website is available at: https://ocaml2025.hotcrp.com/

Please register a description of the talk (typically 2 pages long; it could also be less or more), a clear description 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.

Last year’s accepted presentations are available online.

Evaluation criteria

We will evaluate submissions according to the following aspects:

• relevance for the general OCaml community
• rigor and soundness
• novelty: new concepts/ideas, coverage of something unusual
• clear and understandable exposition of the content
• potential to deliver an engaging and informative (from a theoretical or practical point of view) presentation.

Not all submissions are expected to meet all criteria.

A note on affiliation quota

To guarantee coverage of diverse topics and perspectives, we will introduce a quota of maximum four accepted talks by speakers with the same affiliation, in line with previous workshops. Do not hesitate to submit your talk proposal in any case: quotas will be taken in account by the PC when deciding which submissions to accept. We know that authors may have many affiliations, or affiliations that are very broad (e.g. national research institutes). Judging from previous years we do not expect this to be a problem in most cases: the quota is intended to rule out extreme cases (e.g. having a disproportionate amount of accepted talks from colleagues of the same company).

Attendance

We’re aiming to make the workshop hybrid, meaning that talks as well as participation can be either in-person or remote, and remote attendance will be free. To promote a good atmosphere, communication and engagement, we’ll prefer to have most talks in-person, but remote talks will be most welcome as well.

Thanks to support from the OCaml Software Foundation, registration fees will be covered for speakers in cases they can’t get it funded by other means (e.g. their employer).

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.