ML Family Workshop 2026

ML is a large family of programming languages that includes Standard ML, OCaml, F#, CakeML, SML#, Manticore, MetaOCaml, JoCaml, Alice ML, Dependent ML, Flow Caml, Reason ML, Flix, MaPLe, and many others. All ML languages, besides a great deal of syntax, share several fundamental traits. They are all higher-order, mostly pure, and typed, with algebraic and other data types. Their type systems inherit from Hindley-Milner. The development of these languages has inspired a large amount of computer science research and influenced many programming languages, including Haskell, Scala, Rust, Clojure, and many others.

ML workshops have been held in affiliation with ICFP continuously since 2005. This workshop aims to recognize the entire extended ML family and to provide the forum to present and discuss common issues, both practical (compilation techniques, implementations of concurrency and parallelism, memory management, programming for the Web, modern operating system and network services, platform services – build, document, test, deploy) and theoretical (fancy types, module systems, metaprogramming, etc.) The scope of the workshop includes all aspects of the design, semantics, theory, application, implementation, and teaching of the members of the ML family. We also encourage presentations from related languages (such as Haskell, Scala, Rust, Nemerle, Links, Koka, F*, Eff, ATS, etc), to promote the exchange of ideas and experience.

Note: this year, the workshop will take place across two events: (1) co-located with ICFP’26, and (2) co-located with FW’26. We will have a single Program Committee to review submissions. Presenters can choose either event to attend in-person. We also encourage remote participation, and plan to facilitate remote presentations.

The ML family workshop will be held in close coordination with the OCaml Users and Developers Workshop.

Call for Presentations

ML (originally, “Meta Language”) is a family of programming languages that includes dialects known as Standard ML, OCaml, and F#, among others. The development of these languages has inspired a large amount of computer science research, both practical and theoretical.

The ML 2026 workshop will continue the informal approach followed since 2010. Presentations are selected by the program committee from submitted proposals. There are no published proceedings, so contributions may be submitted for publication elsewhere. The main criterion is promoting and informing the development of the entire extended ML family and delivering a lively workshop atmosphere. We particularly encourage talks about works in progress, presentations of negative results (things that were expected to but did not quite work out) and informed positions.

Each presentation should take 20-25 minutes. The exact time will be decided based on scheduling constraints.

Note: this year, the workshop will take place across two events: (1) co-located with ICFP’26, and (2) co-located with FW’26. We will have a single Program Committee to review submissions. Presenters can choose either event to attend in-person. We also encourage remote participation, and plan to facilitate remote presentations.

Scope

We seek presentations on topics including (but not limited to):

• Language design: abstraction, higher forms of polymorphism, concurrency and parallelism, distribution and mobility, staging, extensions for semi-structured data, generic programming, object systems, etc.

• Implementation: compilers, interpreters, type checkers, partial evaluators, runtime systems, garbage collectors, foreign function interfaces, etc.

• Type systems: inference, effects, modules, contracts, specifications and assertions, dynamic typing, error reporting, etc.

• Applications: case studies, experience reports, pearls, etc.

• Environments: libraries, tools, editors, debuggers, cross-language interoperability, functional data structures, etc.

• Semantics of ML-family languages: operational and denotational semantics, program equivalence, parametricity, mechanization, etc.

We specifically encourage reporting what did not meet expectations or what, despite all efforts, did not work to satisfaction.

Four kinds of submissions are solicited: Research Presentations, Experience Reports, Demos, and Informed Positions.

• Research Presentations: Research presentations should describe new ideas, experimental results, or significant advances in ML-related projects. We especially encourage presentations that describe work in progress, that outline a future research agenda, or that encourage lively discussion. These presentations should be structured in a way which can be, at least in part, of interest to (advanced) users.

• Experience Reports: Users are invited to submit Experience Reports about their use of ML and related languages. These presentations do not need to contain original research but they should tell an interesting story to researchers or other advanced users, such as an innovative or unexpected use of advanced features or a description of the challenges they are facing or attempting to solve.

• Demos: Live demonstrations or short tutorials should show new developments, interesting prototypes, or work in progress, in the form of tools, libraries, or applications built on or related to ML and related languages. (You will need to provide all the hardware and software required for your demo; the workshop organizers are only able to provide a projector.)

• Informed Positions: A justified argument for or against a language feature. The argument must be substantiated, either theoretically (e.g., by a demonstration of (un)soundness, an inference algorithm, a complexity analysis), empirically or by substantial experience. Personal experience is accepted as justification so long as it is extensive and illustrated with concrete examples.

Submission details

Submissions must be in the PDF format and have a short summary (abstract) at the beginning. Submissions in the categories of Experience Reports, Demos, or Informed Positions should indicate so in the title or subtitle. The point of the submission should be clear from its two first pages (PC members are not obligated to read any further.)

Submissions must be uploaded to the workshop submission website before the submission deadline.

Only the short summary/abstract of accepted submissions will be published on the conference website. After acceptance, authors will have the opportunity to attach or link to that summary any relevant material (such as the updated submission, slides, etc.)

Submission Website: [TODO]

Workshop Website: https://icfp26.sigplan.org/home/mlfamilyworkshop-2026

Dates and Deadlines

Submission Deadline: Wed June 24th

(Initial) Author Notification (most cases): Thu July 23th

(Final) Author Notification (if needed): Thu July 30th

Workshop Date: [TBD]

Coordination with the OCaml Users and Developers Workshop

The ML Family Workshop and OCaml Workshop traditionally have been organized in close collaboration. Naturally, there is some overlap between the two workshops, which we are keen to explore in various ways. The OCaml Workshop is dedicated towards the development of the OCaml software ecosystem, focusing on the development of OCaml itself and bringing together the OCaml community. In contrast, the ML family workshop is not focused on any language in particular, is more research-oriented, and deals with general issues of ML-style programming and type systems. Any authors who feel their submission fits both workshops are encouraged to mention it at submission time or contact the program chairs.