The OCaml Planet RSS

Rooted in Cyrus Omar's group's work on the Hazel live programming environment, this talk presents a vision for a "live type-theoretic computational commons": a shared monorepo where humans and swarms of AI agents make verifiable progress on parallel coding tasks. The collaboration model combines novel editing primitives (e.g. CRDT-based structure editing and Unison-style versioning) with familiar type-theoretic structure (e.g. OCaml-style modules and interfaces, Isabelle-style proofs). Two research problems take center stage. First, large-scale collaboration requires that incomplete programs remain continuously analyzable and executable — Cyrus will present recent foundational work on live, incremental type checking and evaluation of programs with typed holes. Second, as agent swarms grow in size and ambition, giving them direct terminal access to our machines and data becomes more risky. He will present a type-theoretic object-capability architecture that provably bounds agent behavior, with per-task capability signatures shaped by humans and weak AI supervisors to enforce the principle of least authority. 00:00:00 – Feedback loops, from pianos to compilers 00:03:29 – The gap problem in dev tools 00:05:07 – A live demo of Hazel: writing quicksort 00:06:19 – Holes, error recovery, and live probes 00:10:14 – "Oops, all threes": debugging with real data 00:12:42 – Demo questions: purity, holes, and call frames 00:25:56 – Graphical notation: tables, dials, and music 00:29:26 – Agentic harnesses and swarms of agents 00:33:33 – Incrementality: re-execution and type checking 00:36:56 – Live incremental IDEs for AI agents 00:41:19 – Collaborative editing for thousands of agents: Grove and Unison 00:44:32 – "Dangerously skip permissions" and object capabilities 00:47:02 – A live computational commons, from Wikipedia to climate models 00:50:24 – Audience Q&A

styled-ppx is a ppx and a library that brings styled components to Melange and OCaml/Reason with type-safe CSS and static extraction. Previously styled-ppx relied on emotion.sh, and from now on, it does not. styled-ppx documentation: https://styled-ppx.vercel.app github repo: https://github.com/davesnx/styled-ppx Remote conf talk releasing styled-ppx (6 years ago!): https://www.youtube.com/watch?v=ekHCBZiCviM GambiConf: How to mimic a JavaScript feature and over-engineering CSS https://www.youtube.com/watch?v=uc5K7Yx0GvQ

The OCaml community participated in the December 2025 round of Outreachy internships. We had four interns working on Raven, OCaml-TIFF and YOCaml. This meeting was an opportunity for the interns to present their work and for the community to as...

A Mechanically Verified Garbage Collector for OCaml (Video, OCaml 2025) Sheera Shamsu, Dipesh Kafle, Dhruv Maroo, Kartik Nagar, Karthikeyan Bhargavan, and KC Sivaramakrishnan (IIT Madras; NIT Trichy, Tiruchirappalli, India; IIT Madras, Chennai; II...

A New Era of OCaml Editing: Powered by Merlin, Delivered via LSP (Video, OCaml 2025) Xavier Van de Woestyne, Sonja Heinze, Ulysse Gérard, and Muluh Godson (Tarides; Tarides; Tarides; Tarides) Abstract: In an era where the number of code editors k...

Embedding WebAssembly in OCaml for Safe Program Construction (Video, OCaml 2025) Hunter DeMeyer (University of Illinois Urbana-Champaign) Abstract: WebAssembly (wasm) is a binary instruction format for a stack-based virtual machine originally des...

How the OCaml Community Established Its Code of Conduct (Video, OCaml 2025) Sudha Parimala (Tarides) Abstract: The OCaml language has been open source since its inception. Originating at INRIA nearly three decades ago, the OCaml ecosystem has had...

OCaml Package Management with (only!) Dune (Video, OCaml 2025) Stephen Sherratt, Marek Kubica, and Rudi Grinberg (Tarides; Tarides; OCaml Labs) Abstract: The OCaml build system Dune keeps track of a project’s dependencies on external software pac...

Taming the Flat Float Array Optimization: Tracking Separability in the Type System (Video, OCaml 2025) Diana Kalinichenko, and Richard A. Eisenberg (Jane Street; Jane Street) Abstract: OCaml’s flat float array optimization stores floating-point v...

Three steps for OCaml to crest the AI humps (Video, OCaml 2025) Sadiq Jaffer, Jonathan Ludlam, Ryan Gibb, Thomas Gazagnaire, and Anil Madhavapeddy (University of Cambridge; University of Cambridge; University of Cambridge; Tarides; University of C...