OCaml

A generic graph library for OCaml.

A large collection of data structures and algorithms for OCaml.

OCaml library for combinatorics https://www.lri.fr/~filliatr/combine/.

A pure OCaml implementation of Zlib.

Fast implementation of queue (FIFO) in OCaml.

Implementation of Rabin's fingerprint and delta compression by P. MacDonald in OCaml (same as libXdiff

Library of Raft consensus algorithm implemented in OCaml

Library of YIQ NTSC transmission image difference alghoritm implemented in OCaml and ReasonML.

A community-maintained foundation library for your OCaml projects.

Declarative definition of command line interfaces for OCaml.

Jane Street Capital's full-fledged standard library overlay. A portable subset of Core is also available: Core_kernel.

Jane Street Capital's dependency-free, quick-compiling, fully-portable across any environment that can run OCaml code standard library.

React is an OCaml module for functional reactive programming (FRP). It provides support for programs with time-varying values, declarative events, and signals.

Minimalist library for command-line parsing.

Pretty-printing library for OCaml.

Light library to deal with RPCs in OCaml.

A lightweight, modular standard library extension, string library, and interfaces to various libraries (bigarrays, Unix, etc.) BSD license.

Micro-benchmarking library for OCaml by Jane Street.   - Getting Started with Core_bench

Benchmarking functions for measuring the run-time of functions using latency or throughput.

In More OCaml, John Whitington takes a meandering tour of functional programming with OCaml, introducing various language features and describing some classic algorithms. The book ends with a large-scale example dealing with the production of PDF files. There are questions for each chapter, along with worked-out answers and hints.

by Allen Downey and Nicholas Monje – How to Think Like a Computer Scientist is an introductory programming textbook based on the OCaml language. It is a modified version of Think Python by Allen Downey. It is intended for newcomers to programming and also those who know some programming but want to learn programming in the function-oriented paradigm, or those who simply want to learn OCaml.

by J. Whitington - OCaml from the Very Beginning will appeal both to new programmers and experienced programmers eager to explore functional languages such as OCaml.

by Richard Bird - It summarizes 30 hard algorithmic problems in the function programming world. Although it is for Haskell, the algorithm problems are very interesting, and trying to solve them in OCaml also helps the thinking of functional programming. Partial solutions in OCaml are here.

by Y. Minsky, A. Madhavapeddy, and J. Hickey - Functional Programming for the masses.

by X. Leroy and D. Rémy – Introduction to Unix Systems Programming, with an emphasis on communications between processes.

This book describes both the OCaml language and the theoretical grounds behind its powerful type system.

This is the first or only book focus on various data structures in FP world. A must-read one.

by Jon Harrop.

Textbook on Functional Programming and Data Structures in OCaml - by Michael R. Clarkson et al.

Mascot is a style-checker for OCaml sources.

pfff is a set of tools and APIs to perform some static analysis, dynamic analysis, code visualizations, code navigations, or style-preserving source-to-source transformations such as refactorings on source code.

Infer is a static analyzer for Java, C and Objective-C

Frama-C is a static analysis and formal proof framework for C and C++.

flow is a static type checker for JavaScript.

SLAyer is an automatic formal verification tool that uses separation logic to verify memory safety of C programs.

MemCAD is an abstract interpreter for shape analysis. MemCAD can verify C programs manipulating complex data structures.

Camelot is a modular and fully configurable OCaml linter and stylechecker.

Translator from OCaml to Coq to formally verify OCaml code.

MOPSA is a generic framework for building sound static analyzers based on the theory of abstract interpretation.

BAP is a reverse engineering and program analysis platform that targets binary programs.

BinCat is a binary code static analysis toolkit.

cwe_checker finds vulnerable patterns in binary executables.

Owi is a toolchain for working with WebAssembly (Wasm) in OCaml, featuring a powerful, parallel symbolic execution engine for Wasm. It also provides frontends for compiling and analyzing C and Rust programs.

Smt.ml is a frontend OCaml library that interfaces with multiple SMT solvers, enabling seamless integration of solvers like Z3, cvc5, Colibri2, Bitwuzla, and Alt-Ergo within OCaml programs.

Languages and Compilers:Caramel - Caramel is a functional language for building type-safe, scalable, and maintainable applications.cDuce - cDuce is a modern XML-oriented functional language with innovative features.Compcert C Compiler - It is a C Compiler supporting most of the ISO C90 and C99 / ANSI C features.Eff Programming Language - Eff is a functional language with handlers of no…

Parser and Lexer Generators:Opal – Self-contained monadic parser combinators for OCaml.Sedlex is a modern, encoding-agnostic (read: Unicode-supporting) lexer generator (the ppx-based successor to ulex.)Menhir – Menhir is a LR(1) parser generator for OCaml.See ocaml-parsing for a …

Articles:Kaleidoscope: Implementing a Language with LLVM in Objective Caml¶

Libraries:Eio — effects-based direct-style IO for multicore OCaml.Miou — a simple scheduler for OCaml 5.Lwt — A cooperative threads library for OCaml.Async — A monadic concurrence library to go with the Core library.

Articles:The blog post that introduced AsyncA user gives up on AsyncCooperative Concurrency in OCaml: A Core.Std.Async Example.

Articles:Implementing the Binary Memcached Protocol with Ocaml and BitstringInterfacing OCaml and PostgreSQL with CaqtiFinally, Type-Safe, Extensible and Efficient Language Integrated Query by Oleg and Co. The proposed approach is to…

Try OCaml in your web browser.

. Web app (written in OCaml) underlying the learn-ocaml-corpus. Can be customized to serve lectures (with Markdown slides), playgrounds (with a toplevel prelude), and interactive exercises (with OCaml tests). MIT License.

. Minor mode for Emacs that can display exercise topics and grade exercise solutions, after logging to a Learn-OCaml instance. MIT License.

An efficient, intuitive, and cross-platform web IDE with your OCaml code interpreted and running in your browser!

Compile and execute OCaml code online.

Learn and execute OCaml code from your iPhone/iPad/Mac.

An OCaml kernel for the Jupyter notebook.

Universal toplevel for OCaml with support for multiline edition, history, real-time and context-sensitive completion, colors, and more.

A command-line tool to format OCaml code.

A source and compiled interface browser, written using LablTk. Included in the standard distribution for ocaml <= 4.01 and with labltk for ocaml >= 4.02.

A command-line tool to manage Github Issues.

Yeoman generator to scaffold OCaml modules.

A PlantUML (.puml) to XML (.xmi) converter.

Foreign Function Interface:ctypes – Library for binding to C libraries using pure OCaml.ocaml-main-program-in-c – Example build system for making mixed C/Ocaml binaries where the main program is in C.Modular foreign function bindingsPy.ml - OCaml bindings for Python.

Editor Integration:ocaml-lsp - An LSP language server for OCaml that integrates with any editor that understands LSP like VSCode, Vim and Emacs.merlin – Context sensitive completion for OCaml in Vim and Emacs.tuareg - OCaml mode for Emacs that can run the toplevel and the debugger within Emacs.[opam-switch-mode](https://github.com/ProofGeneral/op…

Code coverage:Bisect_ppx

. 99% of the solutions are here.

. Corpus of beginner-to-advanced online exercises (including those from the OCaml MOOC) with automatic grading tests.

Exercism is your place to engage in thoughtful conversations about code. Explore simplicity, idiomatic language features, and expressive, readable code. Solutions.

The OCaml section of the book is a free reference for solving common programming problems using OCaml.

Coq is a formal proof management system. It provides a formal language to write mathematical definitions, executable algorithms, and theorems, together with an environment for semi-interactive development of machine-checked proofs.

Why3 is a platform for deductive program verification. It provides a rich language for specification and programming, called WhyML, and relies on external theorem provers, both automated and interactive, to discharge verification conditions.

Alt-Ergo is an open-source SMT solver dedicated to the proof of mathematical formulas generated in the context of program verification.

OCaml library for reading, writing and modifying PDF files.

A neat interface for Slack in OCaml.

Where X=OCaml.

A Unicode library for OCaml.

Multilingualization for OCaml source code. Allows using Unicode identifiers in OCaml source code.

Unicode character database decoder for OCaml.

Unicode character properties for OCaml.

Unicode text normalization for OCaml.

Unicode text segmentation for OCaml.

Non-blocking streaming Unicode codec for OCaml.

GTK2 and GTK3 bindings for OCaml with various higher-level facilities to define GUIs.

QML Qt5 bindings for OCaml.

Interface to the Tcl/Tk GUI framework. In the standard distribution for ocaml <= 4.01.

Tsdl is an OCaml module providing thin bindings to the cross-platform SDL library.

Lambda-Term is a cross-platform library for manipulating the terminal. It provides an abstraction for keys, mouse events, and colors, as well as a set of widgets to write curses-like applications.

Notty is a declarative terminal library for OCaml, structured around the notion of composable images.

Self-contained OCaml bindings to linenoise; easy high-level readline functionality in OCaml.

OCaml pattern-matching extended with regexps

See also: [1], [2], [3].

Standard library for OCaml

C Intermediate Language

formal proof management system

platform dedicated to the analysis of source code written in C

library and tools for accessing and modifying virtual machine disk images

a swiss-army knife for multimedia streaming, notably used for netradios and webtvs

library operating system that constructs unikernels for secure, high-performance network applications across a variety of cloud computing and mobile platforms

cross-platform multi-network peer-to-peer daemon

Native, lightweight modal code editor.

an OCaml API to write static analysis, dynamic analysis, code visualizations, code navigations, or style-preserving source-to-source transformations such as refactorings on source code.

a self-upgradable Proof of Stake blockchain

platform for deductive program verification

management stack that configures and controls Xen-enabled hosts and resource pools, and co-ordinates resources within the pool.

A dumb OCaml logger.

A variant of the Bolt OCaml logging tool.

Logs provides a logging infrastructure for OCaml.

ZeroMQ bindings for OCaml with Async and Lwt wrappers.

nanomsg bindings for OCaml.

OCaml bindings for Apache Kafka.

AMQP client library for Async and Lwt.

Message Passing Interface bindings for OCaml.

OCaml implementation of the MQTT pubsub protocol.

OCaml code generator plugin for the Cap'n Proto serialization framework.

Articles:A Guide to Extension Points in OCamlExtension Points, or how OCaml is becoming more like LispSyntax extensions without Camlp4: let's do it![Reading Camlp4 – Ambassador to the Computers](https://ambassadortothecomputers.blogspot.com/p/reading…

Syntax Extensions:ppx_import – Import is a syntax extension that allows to pull in types or signatures from other compiled interface files.ppx_string_interpolate – A simple ppx filter to support string interpolation like [%str "value of foo is $(foo)"].ppx_monad – Monad syntax extension for OCaml.[ppx_deriving_yojson](https://github.com/whitequark/ppx_derivin…

Tools and Language Extensions:MetaOCaml – an OCaml dialect for multi-stage programming.Fan – Fan is a compile-time metaprogramming system for OCaml, originally inspired from Camlp4. It's a combination of OCaml and Lispy Macros. It shares the same concrete syntax with OCaml.camlp5 - Camlp5 is a preprocessor-pretty-printer of OCaml.[camlp4](http://caml.inria.fr/pub/docs/manual-camlp4/manua…

OCaml client library for Prometheus monitoring.

Articles:OCaml on iOS 7 ReleasedOCaml + Cordova = more secured, typed and hybrid mobile applications

Bindings:Cordova plugins – List of bindings to Cordova plugins. Get access to native device components like accelerometer, SMS, geolocation, etc in OCaml.

HTTP Tools:ocaml-cohttp – Very lightweight HTTP server using Lwt or Async.ocurl – OCaml bindings to libcurl.httpaf – A high performance, memory efficient, and scalable web server written in OCaml.piaf - Client/server library for HTTP/1.X / HTTP/2 written entirely in OCaml.

A pure OCaml implementation of the DNS protocol.

Fluentd logger for OCaml.

charrua-unix is a Unix DHCP daemon based on charrua-core.

Videos available in this playlist of the OCaml Software Foundation YouTube channel.

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Course that uses OCaml to teach functional programming and programming language design

Distribution:OPAM – A flexible Git-friendly package manager with multiple compiler support.ocamlfind — Local OCaml library manager. Used by most of the OCaml ecosystem.OCaml for Windows - opam repository and experimental build for Windows (deprecated since 2021).Diskuv OCaml - Diskuv OCaml distribution f…

Build Tools:dune – A composable and opinionated build system for OCaml (former jbuilder)Oasis - A tool to integrate a configure, build and install system in your OCaml project. It helps to create standard entry points in your build system and allows external tools to analyse your project easily.oasis2opam — Tool to convert OASIS metadata to OPAM package descriptions.[obuild](https://…

Libraries:Parmap — Provides easy-to-use parallel map and fold functions.ForkWork — A simple library for forking child processes to perform work on multiple cores.Functory — A distributed computing library which facilitates distributed execution of parallelizable computations in a seamless fashion.Rpc.Parallel — A library for spawning pro…

Articles:What is the state of OCaml's parallelization abilities?Parallel programming in multicore OCamlParallelism programming from the officiel OCaml manualAwesome multicore OCaml. A compilat…

’s [@@deriving show].

, a ppx_deriving-like.

, another ppx_deriving-like.

, again a ppx_deriving-like.

, probably a ppx_deriving-like with ppx_typerep_conv.

, which appears to have the user build the type representation manually from combinators in addition to also having the user pass it where needed.

, also fully manual.

, fully manual.

in Dune. It appears to also be fully manual.

The drom tool is a wrapper over opam/dune in an attempt to provide a cargo-like user experience.

Reason and Ocaml project generator

Template for an ocaml project with modern tooling

OCaml Bioinformatics Library http://biocaml.org.

OCaml library for building bioinformatics pipelines.

OCaml bindings for BLAS/LAPACK (high-performance linear algebra Fortran libraries).

OCaml library for multi-armed bandits.

Numerical library for OCaml.

OCaml library for general numerical work.

Bindings to frequently used C special functions library.

A linear algebra library in OCaml with type-based static size checking for matrix operations.

OCaml bindings for TensorFlow.

OCaml numerical library: dense and sparse matrix, linear algebra, regressions, maths and stats functions.

A system designed for the efficient calculation of multi-particle scattering cross sections and simulated event samples.

a pure OCaml regular expressions library with combinators, supporting several formats (glob, posix, str, etc.).

bindings to the PCRE library (perl-compatible regular expressions)

Humane-re attempts to provide an easy interface for 90% of your regex needs. Courtesy of ocaml-re.

Tyre is a set of combinators to build type-safe regular expressions, allowing automatic extraction and modification of matched groups.

TLS in pure OCaml.

Hash algorithms (like SHA* or BLAKE2*) in OCaml and C.

The Cryptokit library for OCaml provides a variety of cryptographic primitives that can be used to implement cryptographic protocols in security-sensitive applications.

A Commitment scheme library for Multi-party computations such as online auctions and gambling.

A small cryptographic library behind the ocaml-tls project. It is built to be straightforward to use, adhere to functional programming principles, and able to run in a Xen-based unikernel.

OCaml library to manipulate RDF graphs and execute Sparql queries.

A serialization compiler for multiple languages (OCaml, Java, Python, Scala, Typescript) with a Binou or JSON format

Bencode (.torrent file format) reader/writer.

Extensible binary data format, like JSON but faster.

OCaml native CBOR decoder/encoder.

Non-blocking streaming JSON codec for OCaml.

A streaming codec to decode and encode the XML data format.

An optimized parsing and printing library for the JSON format.

A S-expression parser and printer

Mirage is a programming framework for constructing secure, high-performance network applications across a variety of cloud computing and mobile platforms.

Read and write FAT-format filesystems from OCaml.

Pure OCaml low-level git bindings.

Pure OCaml implementation of the "vchan" shared-memory communication protocol.

Embedded systemsOMicroB - A virtual machine designed to run OCaml bytecode on AVR (Arduino for instance) micro-controlers.OCaPIC - An OCaml virtual machine for PIC18 micro-controlers.ocaml-esp32 - A compiler for ESP32 SoC.

A lightweight and colourful test framework.

OUnit is a unit test framework for OCaml. It allows one to easily create unit-tests for OCaml code. It is based on HUnit, a unit testing framework for Haskell.

QCheck is a property testing library inspired from Haskell's QuickCheck

(formerly known as qtest) — supports inline pragma's to generate tests.

comprehensive testing framework.

General inline testing macro's.

A lightweight unit testing framework compatible with the Test Anything Protocol.

A framework for writing tests in OCaml, similar to Cram, developed by JaneStreet.

Collision-resistant IDs for server scalability & database performance.

PPX deriver designed to streamline the process of validating records.

Uuidm is an OCaml module implementing 128-bit universally unique identifiers version 3, 5 (name based with MD5, SHA-1 hashing) and 4 (random based) according to RFC 4122.

Official OCaml port of Sqids. Generate short unique IDs from numbers.

Frameworks:Opium – Sinatra like web toolkit for OCaml.Ocsigen Eliom – Eliom is a full-featured multi-tier framework, for developing multi-platform Web and mobile apps as 100% OCaml distributed applications. It can also be used for more traditional Web or mobile apps: Web sites, single page applications, REST API, etc.Dream - Tidy Web framework for OCaml and ReasonML[webmachine](https://git…

Tools:COW – Caml on the Web (COW) is a set of parsers and syntax extensions to let you manipulate HTML, CSS, XML, JSON and Markdown directly from OCaml code.Ocamlnet has many relevant web libraries — Nethtml html parser, Netasn1 …

Open Source Projects:Cumulus – Hacker news like website with the OCaml framework Ocsigen