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Companies using OCaml

“OCaml helps us to quickly adapt to changing market conditions, and go from prototypes to production systems with less effort ... Billions of dollars of transactions flow through our systems every day, so getting it right matters.” — Jane Street


Facebook, United States

Facebook has built a number of major development tools using OCaml. Hack is a compiler for a variant of PHP that aims to reconcile the fast development cycle of PHP with the discipline provided by static typing. Flow is a similar project that provides static type checking for Javascript. Both systems are highly responsive, parallel programs that can incorporate source code changes in real time. Pfff is a set of tools for code analysis, visualizations, and style-preserving source transformations, written in OCaml, but supporting many languages.

Bloomberg L.P.

Bloomberg L.P., United States

Bloomberg, the global business and financial information and news leader, gives influential decision makers a critical edge by connecting them to a dynamic network of information, people and ideas. Bloomberg employs OCaml in a advanced financial derivatives risk management application delivered through its Bloomberg Professional service.


Citrix, United Kingdom

Citrix uses OCaml in XenServer, a world-class server virtualization system. We also offer a full open-source variant of XenServer called the Xen Cloud Platform, or XCP. Follow along with our OCaml development at github.com/xen-org. This work was originally presented by Anil Madhavapeddy at CUFP 2008. See his abstract and slides.


Acunu, United Kingdom

Acunu is writing, from the ground-up, a Storage and Analytics Platform for Massive Data.


Ahrefs, Singapore

Ahrefs is a multinational team with roots from Ukraine and headquarters in Singapore. Ahrefs history dates back to 2011 when our first version of Site Explorer was introduced to public after one year of thorough preparation and data mining. With the launch of Site Explorer, Ahrefs stirred the stagnant field of backlink analysis and kick-started a new round of competition among SEO tool providers back then and quickly became one of the world 's best backlink analysis tools. Today, our index is updated with freshest backlinks found on the web every 15 minutes, and the crawler processes up to 6 billion pages a day. Hard to believe – it is only three times less than what Googlebot does!


American Museum of Natural History, United States

The Computational Sciences Department at the AMNH has been using OCaml for almost a decade in their software package POY for phylogenetic inference. See AMNH's GitHub page for more projects.


ANSSI, France

The ANSSI core missions are: to detect and react to cyber attacks, to prevent threats, to provide advice and support to governmental entities and operators of critical infrastructure, and to keep companies and the general public informed about information security threats. See ANSII's GitHub page for some of its OCaml software.

Ashima Group

Ashima Group, United States

Ashima Group uses OCaml for geometric reasoning, GPU shader translation, and high-performance servers. OCaml's type system, compiler, tools, community, and design philosophy make it an extremely powerful and versatile tool for diverse systems development tasks.


CACAOWEB, United Kingdom and Hong Kong

Cacaoweb is a developing an application platform of a new kind. It runs on top of our peer-to-peer network, which happens to be one of the largest in the world. The capabilities of the platform are diverse and range from multimedia streaming to social communication, offline storage or data synchronisation. We design and implement massively distributed data stores, programming languages, runtime systems and parallel computation frameworks.


CEA, France

CEA is a French state company, member of the OCaml Consortium. It uses OCaml mainly to develop a platform dedicated to source-code analysis of C software, called Frama-C.

Coherent Graphics

Coherent Graphics Ltd, United Kindgom

Coherent Graphics is a developer of both server tools and desktop software for the processing of PDF documents. We use OCaml as a general-purpose high level language, chosen for its expressiveness and speed.


Cryptosense, France

Based in Paris, France, Cryptosense creates security analysis software with a particular focus on cryptographic systems. A spin-off of the institute for computer science research (Inria), Cryptosense’s founders combine more than 40 years experience in research and industry. Cryptosense provides its solutions to an international clientèle in particular in the financial, industrial and government sectors.


Dassault Systèmes, France

Dassault Systèmes, the 3DEXPERIENCE Company, provides businesses and people with virtual universes to imagine sustainable innovations.

Digirati dba Hostnet

Digirati dba Hostnet, Brazil

Digirati dba Hostnet is a web hosting company. We use OCaml mostly for internal systems programming and infrastructure services. We also have contributed with the community by releasing a few open source OCaml libraries.

Digital Solutions

Digital Solutions, Uganda

General programming, with wide base and experience in Mobile Telephony programming and web application development.


Esper, United States

Esper's software assists assistants. In doing so, we save the time of executives. We want to lead the way to a more productive world with an assistant for every professional and Esper for every assistant. We envision a future without endless e-mail scheduling, without cognitive overload, and where technology serves us, not distracts us. To accomplish these goals, we're building a mobile/web suite that streamlines communication between assistants and executives, automates rote tasks, and shares information.

Our Web backend is written in OCaml and provides an API used by our own Web, Android, and iOS clients.

Esterel Technologies

Esterel Technologies, France

Esterel Technologies is a leading provider of critical systems and software development solutions for the aerospace, defense, rail transportation, nuclear, and industrial and automotive domains.


Fasoo, Korea

Fasoo uses OCaml to develop a static analysis tool.

Flying Frog

Flying Frog Consultancy, United Kindgom

Flying Frog Consultancy Ltd. consult and write books and software on the use of OCaml in the context of scientific computing. OCaml excels in the niche of intrinsically complicated programs between large-scale, array-based programs written in languages such as HPF and small-scale, graphical programs written in languages such as Mathematica.


ForAllSecure, United States

ForAllSecure's mission is to test the world's software and provide actionable information to our customers. We have started with Linux. Our mission with Linux is to test all programs in current distributions, such as Debian, Ubuntu, and Red Hat. With time, we will cover other platforms, such as Mac, Windows, and mobile. In the mean time, we promise to do one thing well.


Framtidsforum I&M, Sweden

Framtidsforum I&M sells ExcelEverywhere, which creates web pages that look and function the same as your MS Excel spreadsheet. JavaScript is used for calculation. Supports 140 Excel-functions. Typically used for expense report, survey, order forms, reservation forms, employment application, financial advisor, ROI. There are also versions that generate ASP, ASP.NET and JSP/Java code. The compiler is written using OCaml.


Galois, United States

Galois has developed a domain specific declarative language for cryptographic algorithms. One of our research compilers is written in OCaml and makes very extensive use of camlp4.


Incubaid, Belgium

Incubaid has developed Arakoon, a distributed key-value store that guarantees consistency above anything else. We created Arakoon due to a lack of existing solutions fitting our requirements, and is available as Open Source software.

IT Planning

IT Planning, Japan

We use OCaml for some kind of enterprise systems (i.e. production control, portfolio risk management and web services).

Jane Street

Jane Street, United States

Jane Street is a quantitative proprietary trading firm that operates around the clock and around the globe. They bring a deep understanding of markets, a scientific approach, and innovative technology to bear on the problem of trading profitably in the world's highly competitive financial markets. Jane Street is perhaps the largest commercial user of OCaml, and has attracted a very strong team of functional programmers. They use OCaml for everything, from research infrastructure to trading systems to operations and accounting systems. Jane Street has over 50 OCaml programmers and over a million lines of OCaml, powering a technology platform that trades billions of dollars every day. See the GitHub page for their open source software.


LexiFi, France

LexiFi is an innovative provider of software applications and infrastructure technology for the capital markets industry. LexiFi Apropos is powered by an original formalism for describing financial contracts, the result of a long-term research and development effort.


MEDIT, France

MEDIT develops SuMo, an advanced bioinformatic system for the analysis of protein 3D structures and the identification of drug-design targets. SuMo is written entirely in OCaml and provides interfaces to several commercial molecular-modelling packages.


MLstate, France

MLstate is the creator of Opa: an open-source web development platform. It consists of a new programming language, a new web server, a new database and a new distributed execution engine, all of them tightly integrated to provide a great experience for web developers. Opa is concise, simple, concurrent, dynamically secure and secure out of the box. It is written mainly in OCaml and uses OCaml as an intermediate language for compilation.


Monoidics, United Kingdom

Monoidics develops Infer, a static analyzer for software verification. The analysis engine is entirely written in OCaml.

Mount Sinai

Mount Sinai, United States

The Hammer Lab at Mount Sinai develops and uses Ketrew for managing complex bioinformatics workflows. Ketrew includes an embedded domain-specific language to simplify the specification of workflows and an engine for the execution of workflows. Ketrew can be run as a command-line application or as a service.

Mr. Number

Mr. Number, United States

Mr. Number started as a Silicon Valley startup and developed the Mr. Number app for call blocking, later acquired by WhitePages. OCaml is used on the server side as the glue between the various third-party components and services.


MyLife, United States

MyLife has developed a powerful people search tool that will empower those in need to find anyone, regardless of years past and the life that was built in between.

Narrow Gate Logic

Narrow Gate Logic, Poland

Narrow Gate Logic is a company using the OCaml language in business and non-business applications.


OCamlPro, France

OCamlPro develops and maintains a development environment for the OCaml language. They provide services for companies deciding to use OCaml. Among these services: trainings, necessary expertises, tools and libraries long-term support, and specific developments to their applicative domains.

PRUDENT Technologies

PRUDENT Technologies and Consulting, Inc., United States

Prudent Consulting offers IT solutions to large and mid-sized organizations by combining industry experience and technology expertise to help our customers achieve business goals with speed, agility and great impact.


Psellos, United States

Psellos is a small group of computer scientists who became intrigued by the idea of coding iOS apps in OCaml. It has worked out better than we expected (you can buy our apps in the iTunes App Store), and at least one other company sells apps built with our tools. Our most recent iOS cross compiler is derived from OCaml 4.00.0.


RunOrg, France

RunOrg provides non-profits and organizations with a private intranet and public website using a SaaS model. The application is written entirely in OCaml for two reasons : one is performance, as OCaml generates fast binaries and supports elegant optimization patterns. The other reason is that the flexible and powerful compile-time type inference allows massive changes in the code base without causing any bugs, effectively acting as a compiler-generated unit testing suite. The software is powered by an open source in-house web framework, Ohm.


Sakhalin, United States

Sakhalin develops marine charting apps for Apple iPads and iPhones. The full featured apps display marine charts, GPS and onboard sensor data, Automatic Identification System, weather data, anchor monitoring, etc. The apps have a wide range of users, from occasional recreational boaters to professional river/harbor pilots that board large freighters. They are free to download and try (with a paid upgrade to enable all features). They are written almost entirely in Ocaml with a minor amount of glue to interface with IOS API's. Ocaml was chosen because it (1) enables the rapid development of extremely reliable and high performance software, (2) is a mature stable platform, and (3) has a wide range of libraries. It was made possible by the great work done by Psellos in porting OCaml to the Apple iOS platform. Feel free to contact Sakhalin if you have any questions about using OCaml on iOS.

Shiro Games

Shiro Games, France

Shiro Games is developing games using Haxe, a language built with a compiler written in OCaml.


Sleekersoft P/L, Australia

Specialises in functional programming software development, consultation and training.

Studio Associato 4Sigma

Studio Associato 4Sigma, Italy

4Sigma is a small firm making websites and some interesting web applications. OCaml is not the main language used but it is used here and there, particularly in a small server that is a key component of a service we offer our customers.

Vector Fabrics

Vector Fabrics, The Netherlands

Vector Fabrics is a high-tech software company, developing tools for embedded multicore programming. Its technology and expertise is getting widespread recognition in the industry as being innovative and unique in their ability to address heterogeneous multicore application-specific silicon platforms. Due to the advanced nature of its tools, Vector Fabrics operates at the forefront of the next generation of embedded platforms for diverse markets ranging from supercomputers to automotive to cell phones.


Appearance of a company's name here does not necessarily imply endorsement by that company of OCaml or of the descriptions provided here. Company representatives should contact us to have information about their company removed, modified, or added.