Learn OCaml the Easy Way - Including the Hard Bits

OCaml is a valuable and powerful tool, combining performance, security, and reliability. Joining the ecosystem, community, and learning the language can help you make the most of its capabilities if you're not already familiar with it. But how can we make learning OCaml easier? As with other functional programming languages, its visibility can be limited by factors such as your educational and professional environment, or the programmers you follow. Nevertheless, the world of software development is increasingly recognising the strengths of functional programming in general and OCaml in particular.

To meet the growing interest in OCaml, we aim to make learning the language as straightforward as possible. For individuals, we’re prioritising tutorials, books, and events centred around OCaml. For teams and organisations, we offer OCaml courses for both basic and advanced training.

The Best Ways to Learn OCaml: For the Independent Learner

OCaml.org

Whether you’re looking to write a ‘hello world’ or delve into the details of the OCaml compiler, the central resource is OCaml.org. The Learn area provides a range of resources, including tutorials, exercises, and a directory of books and academic papers, catering to different skill levels. The page also offers ways to install the latest version of OCaml, access the manual, and explore OCaml’s documentation. The team has taken inspiration from other languages like Python, Rust, and the functional language Haskell to improve the resources available to learn OCaml.

These resources are tailored to the independent learner, using their free time to pursue knowledge, or the teacher needing materials for their students. We support the continuous improvement of tutorials and documentation on OCaml.org, and the accessibility of books, papers, and other learning materials. The pages are also open-source, meaning that everyone is welcome to contribute!

Books

If you prefer learning from books, there are several available to choose from. For beginners, OCaml Programming: Correct + Efficient + Beautiful and OCaml From the Very Beginning are excellent choices. The former is a textbook used at Cornell University, complete with a video playlist. Intermediate learners may find Real World OCaml and More OCaml: Algorithms, Methods, & Diversions beneficial. Real World OCaml is available for free download thanks to our sponsorship of its gold open access release.

Community

OCaml’s robust open-source ecosystem significantly aids newcomers by making source code freely available for study, and offering access to experts and feedback through the GitHub repository and Discuss forum.

There are many more ways to engage with the OCaml community online:

• Social media: head over to the Community page on OCaml.org for an overview of the different places online people meet to discuss, develop, and blog about OCaml. Resources include more or less formal forums, educational text- or video-based content, entertainment, social networking, and live chats.
• Advent of Code: An advent calendar of programming puzzles, suitable for a variety of skill levels and compatible with all languages, popular with programmers as a way to challenge themselves and learn new languages. This year, Sabine has organised a leaderboard for people solving the advent of code in OCaml.
• The OCaml Planet: An RSS feed aggregator hosted on OCaml.org which shares articles and blog posts on everything OCaml. Follow it to stay up-to-date on the latest OCaml news, technical deep dives, open-source project updates, and developer insights.

Events

We also host and sponsor community events like hacking days and conferences to further support users who want to learn more about OCaml. Upcoming events include:

• The OCaml Workshop: Continuing in a well-established tradition, the OCaml Workshop will be held at the 2025 ICFP Conference. With a more academic focus, talks start out as papers which are then presented as part of the OCaml track.
• The FUN OCaml Conference: Returning for a second time in 2025, the new OCaml conference is organised by developers for developers and covers topics big and small.
• Reason OCaml India Meetups: A community of Reason and OCaml enthusiasts that organise regular in person and online meet-ups.

There are of course many more events organised outside of those we host and sponsor, and some notable examples are Functional Conf and OUPS. We recommend that you check out the Events page to get an overview of all the great OCaml events you could join!

The Best Ways to Learn OCaml: Tailored Training in OCaml

In large organisational teams, relying on individual learning or the dissemination of knowledge from a few experts can be time-consuming and inconsistent. Tailored courses enable simultaneous training for the entire group, fostering collaboration in tackling new challenges. To make learning OCaml easier for groups, we’ve created courses to enhance team competence in the language. Here’s what our OCaml courses offer.

Our Foundational Course Starting with OCaml: An Introduction

This course teaches core OCaml programming concepts through theory and practice, and has been designed to facilitate a smooth transition for engineers from other languages, including imperative programming. It covers OCaml’s history, design choices, and key functional programming concepts such as functions, recursion, and higher-order functions alongside critical concepts like tuples, the OCaml type system, type inference, pattern matching, and polymorphism.

The bulk of the course comprises several modules that introduce the practical building blocks of programming with OCaml. This includes methods: imperative and modular programming, data structures, error handling, interfacing with C, and command-line parsing. It also offers guidance on tooling: opam, Dune, VSCode, debugging and profiling, concurrent programming with lwt, and testing using expect tests and QuickCheck.

Finally, the course would not be complete without hands-on experience writing OCaml code. The modules on setting up the OCaml environment, building, documenting, and releasing an OCaml project culminate in an entire day spent on building an OCaml application from scratch. Participants will leave with a solid understanding of OCaml, the necessary tools for development, and practical application-building experience. Following this foundational course, your entire team will be familiar with the OCaml language and workflow.

Our Higher-Level Course Mastering OCaml: Advanced Techniques

The advanced course is designed for experienced users and teams looking to enhance their skills. It consists of three sections: advanced OCaml techniques, advanced methods for common OCaml tools, and advanced tooling.

Advanced OCaml techniques make up the bulk of the course, including generalised algebraic data types (GADTs), multicore programming with OCaml 5, and transitioning from OCaml 4 to OCaml 5. Advanced methods for common OCaml tools cover using the Dune build system, and PPX preprocessors.

Topics in advanced tooling include: the MirageOS library operating system for secure, high-performance, network applications; web development with JS_of_ocaml, Wasm_of_ocaml, and Dream; concurrent programming with [Eio], and using property-based testing to evaluate programs. This course aims to equip teams already using OCaml with new skills and tools. An advanced course with deep topics, the course is tailored to focus on relevant areas for your team, taking them to the next level.

Finally, one of the biggest benefits we offer with our courses is customisation. We understand that teams have unique challenges and goals, and offer you the option to create a course that fits your needs. Not only can you pick a selection of topics from the advanced OCaml modules, but you can completely tailor the training with a customised itinerary. This is negotiated on a per-instance basis, and you can schedule a free consultation to discuss what that could look like for your teams.

Get in Touch

Need help learning OCaml? Reach out to the community on Mastodon, X, or LinkedIn to get helpful pointers or ask questions on Discuss. If you’re interested in our courses for your teams, you can get a free consultation to discuss whether the curriculum is right for you and sign up to our mailing list to receive the latest news.

We look forward to hearing from you, please don’t hesitate to get in touch!