This is an update on recent works of the OCaml Software Foundation, covering our 2025 actions – the previous update was in January 2025. (In the present thread I will mention things that we agreed to fund in 2025; many of the actions that actually happened in 2025 were approved in 2024 and are listed in the previous thread.)
The OCaml Software Foundation is a non-profit foundation that receives funding from industrial sponsors each year, and tries its best to spend it to support and strengthen the OCaml ecosystem and community.
The funding volume we receive each year is around 200K€. (For comparison: this is the yearly cost of one experienced full-time software engineer in many parts of the world.) We do not fund people full-time for long periods. Most actions receive from 3K€ to 20K€. The work to prepare and execute actions is mostly done by the (unpaid) Executive Committee. It is currently formed by Nicolás Ojeda Bär, Damien Doligez, Xavier Leroy, Kim Nguyễn, Virgile Prevosto and myself, with administrative personnel provided by INRIA and general assistance by Alan Schmitt.
Our current sponsors (thanks!) are ahrefs, Jane Street, Tezos, Bloomberg, Lexifi, SimCorp, and MERCE. (If your company would like to join as a sponsor, please get in touch. Unfortunately, we still cannot efficiently process small donations, so we are not calling for individual donations.)
Feel free to use this thread for questions/suggestions 
Education and outreach
We keep funding the OCaml meetups in Paris and Toulouse, France. The meetup in Chennai, India unfortunately seems to be inactive currently. A new meetup is starting in London ( [ANN] Caml in the Capital ), we are setting up funding. (If you want to start an OCaml meeting in some other place, please do not hesitate to get in touch!)
We sponsored the JFLA 2026, a functional programming conference in France.
We also sponsored ICFP 2025 in Singapore, and provided financial support for the colocated OCaml Workshop 2025, for PC members and speakers who could not otherwise cover the travel and registration costs.
We recently started funding Thomas Leonard for his time writing excellent technical blog posts about OCaml. The first blog post covered by this support is on his new OCaml library and tool for linux mode setting (very technical!).
Research
The OCaml Software Foundation is typically not involved in funding research, focusing on actions that have a more immediate impact on the language and its community. We do provide recurrent funding to the Cambium research team at INRIA, which corresponds to the funding they received from the OCaml consortium before the OCaml Foundation was created.
This year we also agreed to fund a grant for a long internship on Cameleer, a program-verification tool for OCaml on top of the Why3 verification environment. Mário Perreira, funding recipient and author of Cameleer, also wrote a book on the tool with his student Pedro Gasparinho.
Finally, Jane Street agreed to provide additional funding (roughly one person-year) for the professional expenses of people at INRIA who work on the OCaml compiler.
Ecosystem
Compiler
We supported Tarides for some (a small portion) of the time spent by David Allsopp and Olivier Nicole on compiler maintenance.
We funded Clément Blaudeau to work on the implementation of the OCaml module system, as a more practical follow-up after his PhD on the OCaml module system. Clément found many small issues and started fixing them, and is now working on a much more ambitious plan for ‘transparent ascriptions’ in OCaml, which could improve module-checking performance and is a requirement for modular implicits.
We funded Pierre Boutillier to work on the OCaml bytecode debugger. Pierre Boutillier wanted to provide built-in support for running ocamldebug from Dune, an equivalent of dune utop for a toplevel. He completed the compiler side of the work, but he moved to a different full-time job before attacking the Dune side.
We funded Thomas Refis to review the “Type error recovery” PR from Xavier van de Woestyne (Tarides), which upstreams a part of the Merlin changes to the typechecker, to make Merlin maintenance easier in the future.
We funded Jan Midtgaard to keep working on his multicoretests fuzzing suite, which has found various Multicore-related correctness issues in the OCaml runtime and standard library.
Infrastructure
As in previous years, we funded the work of Kate Deplaix to check that the OCaml ecosystem is compatible with upcoming compiler releases.
We are trying our best to support the work of opam-repository maintainers, through individual funding grants for the active maintainers. This year we supported Tarides for some of the time of Shon Feder on the opam-repository, and we fund Jan Midtgaard for opam-repository maintenance, with in particular a focus on Windows and FreeBSD support.
Probably the biggest “infrastructure” change which involved the Foundation this year is the OCaml Security Team, which was created by the Foundation as a result of a proposal by Tarides, with in particular generous financial support of Bloomberg. The Security Team just published their own activity report.
Tools
We funded the maintenance of ppxlib by Nathan Rebours.
We funded development on the opam client by Raja Boujbel (OCamlPro).
We funded contributions of Ali Caglayan to dune.
We funded Jules Aiguillon (Tarides) to update ocamlformat for OCaml 5.5.
Libraries
We supported the work of Petter Urkedal on the Caqti library, the main database connection library in the OCaml community.
We supported the maintenance of the Ocsigen web toolkit.
We funded the maintenance of ctypes.
We funded Thomas Leonard to work on a Wayland window manager in OCaml.
We supported the contributions of Daniel Bünzli to the OCaml ecosystem. This year, Daniel used this support to fund the development of
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support for Unicode 17.0 in his Unicode libraries
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bytesrw, a library of composable byte stream readers and writes, extended in version 0.3 for support with various TLS-related crypto algorithms.
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the 0.4 release of Cmarkit, a CommonMark parser and renderer.
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release 2.0.0 of the Cmdliner library for command-line argument parsing, bringing support for manpage installation and auto-completion.