Six Surprising Reasons the OCaml Programming Language is Good for Business

by Isabella Leandersson on Nov 22nd, 2022

Functional programming languages have been around since the 1950's, when the first high-level languages were used to program early computers. Examples of functional programming languages include OCaml, Erlang, Clojure, Haskell, Scala, and Common Lisp. Choosing the right programming language is critical to the long-term success and stability of your products, services, and operations. With strong academic roots and years of iteration and innovation, functional programming languages can offer a real competitive edge to businesses. This article explains some of the lesser-known benefits of OCaml from a business perspective.

Why Functional Programming?

The strengths of functional programming are becoming increasingly well-known. Functional programming lets programmers write programs in a declarative, logical, and mathematical style. This makes it easier for the developer to express their intent in a declarative style, where the code closely matches the specification. A specification is a mathematical description of what a program does, and programs that match their specification are proven to follow that description, which makes them predictable and safe. Furthermore, with features that limit the mutation of data and side effects, functional programs tend to have fewer bugs and vulnerabilities, remain easy to develop and maintain, and last longer overall.

Nowadays, widely-used imperative programming languages such as Python, Rust, and Java support programming in a functional style and use functional programming features to take advantage of its strengths. Features like rich type systems, pattern matching, and lambda expressions are becoming more mainstream, illustrating their usefulness.

What Makes OCaml Unique?

OCaml combines a strong foundation in functional programming with some select imperative and object-oriented programming features, allowing the user to choose the best approach for the task at hand. This is part of what makes OCaml such a great general-purpose programming language; it combines the strengths of several programming styles and offers the developer a full software development toolkit.

OCaml provides a unique balance of performance, security, and reliability. It combines features like a garbage collector, static type-checking, type-driven development, first-class functions, and pattern matching (features that work well together). Together they result in a language known for minimising errors, debugging easily, automatically managing memory, preventing structural errors in data, and providing a user-friendly developer environment.

When OCaml 5 is released later this year, the language will get a significant upgrade, introducing support for shared-memory parallelism and native support for simple concurrent programming. Running programs on multiple cores will allow developers to considerably reduce the runtime of their projects by executing code in parallel. The quality-of-life updates to concurrent programming will make it easier for developers to write high-performance concurrent code.

So what are some of OCaml’s greatest strengths? Here are the key reasons why businesses use OCaml to solve complex, critical, and time-sensitive problems.

1. OCaml Is Trusted By Several Prominent Companies

Think of OCaml as an academic language? Think again! Owing to its reputation for reliability, safety, and performance, many businesses use it to solve real-world problems. Talented software engineers all over the world create robust, maintainable, energy-efficient, and fast solutions in OCaml for high-pressure environments where a single mistake can cost millions.

Docker is making life easier for developers by providing them with a state-of-the-art integrated development pipeline that consolidates application components, all available conveniently on your desktop. Docker has over fifteen million registered users worldwide and uses VPNKit, which is written in OCaml, in its Docker Desktop app to keep user networks secure.

Meta is a multiplatform company that uses tech to bring people together and build unique communities online. The social media giant uses OCaml in major parts of its infrastructure, such as the compiler and typechecker for its programming language Hack. Other Meta tooling that uses OCaml includes Infer, Flow, and the now retired Pfff.

Jane Street is a quantitative trading firm that uses OCaml as their core solution for their research tools, trading systems, and accounting systems. Processing billions of dollars each day, Jane Street relies on OCaml to ensure it is done securely and quickly. Notably, nearly a million lines of their code is open source, and they work closely with the OCaml community to develop the language and its tools.

Other companies that use OCaml include Ahrefs, an all-in-one SEO tool; Nitrokey, a world-leading provider of open-source security hardware; and Hyper, who use OCaml to provide their customers with a unified data platform to manage large infrastructure. There are also two blockchains written in OCaml: Tezos and Mina. When it comes to the modern landscape of software development, it is safe to say OCaml has an ever-growing part to play.

The Takeaway : Several top companies are already using OCaml, so there is a strong tradition of successfully using OCaml on an industrial level.

2. OCaml Has a Growing and Thriving Community

The open-source community surrounding OCaml is diverse and flourishing. It congregates in several places online, like the Discuss forum, GitHub repo, and Reddit community. Thanks to its increasing popularity, more and more tutorials and documentation are becoming available online. Learning new languages with the help of online material is the trend nowadays, and OCaml welcomes all developers with open arms. In fact, there is a great book for learning OCaml entirely available online called Real World OCaml.

Over thirty universities currently teach OCaml, including the University of Cambridge, Paris-Diderot University, the Indian Institute of Technology Madras, Harvard, and Cornell University. Cornell University has a great textbook on OCaml. Students who learn OCaml often end up becoming part of its open-source community, contributing to projects and launching initiatives of their own. Companies that use OCaml to provide their customers with great products also contribute to the OCaml community, as do academics, researchers, and hobbyists. All entry-points contribute to the development of the language, and users end up interacting with each other across these categories, each bringing their own unique perspective.

The Takeaway : The community surrounding OCaml is vibrant and thriving, allowing you to invest your time and energy in OCaml knowing it’s here to stay.

3. OCaml Offers Powerful Tools and Plenty of Support

OCaml is not only an industrial-strength programming language, but it also provides industry-ready tooling and ecosystem support. The OCaml Platform is a curated set of tools that have broad community support. It includes all the tools you'd expect from an industrial-strength programming language, including a build system, package manager, editor support, and documentation generator. The OCaml Platform tells you whether one of these tools is active, under incubation, or deprecated. The OCaml Platform ensures that developers not only have an excellent language at hand but also have the tools to productively develop software with that language. Furthermore, the OCaml website has thorough resources on everything OCaml, including a comprehensive guide to setting up OCaml on your computer.

The OCaml compiler is regularly updated and has a dedicated team focused on innovation, improving new features, and keeping everything bug-free. If you have a problem or need help, the response time across the various OCaml forums is very quick and supportive of new learners. Recently, the aforementioned great and comprehensive book Real World OCaml has been updated for its 2nd edition. This edition is available to download online as a free PDF to make learning OCaml even more accessible.

If you want to create something new in OCaml, or need help building something, there are several companies as well as hobbyist groups to consult. You can find like-minded people to discuss your ideas with on the OCaml forum Discuss. Tarides is one of the companies that regularly work on OCaml, so you can send us a message if you’d like help with a project.

The Takeaway : OCaml offers several up-to-date tools supported by an active group of contributors and maintainers. Using OCaml means getting help fast and having a complete developer environment with everything you need.

4. OCaml is Secure-By-Design

In today’s connected world, keeping yourself and your data safe online is not just a matter of convenience, but it's also a crucial task that can have serious personal and professional repercussions. Luckily, the OCaml programming language is built in a way that promotes safety, including features and design patterns that make it secure-by-design. It's easy to integrate formally verified code with OCaml programs, which makes OCaml more secure. Some formally verified libraries available in OCaml include Microsoft's HACL* and MIT's Fiat.

Secure-by-design is a known programming term which means that a language is constructed in a way that fundamentally promotes security and minimises vulnerabilities. A language that is secure-by-design makes it impossible to introduce a large class of security vulnerabilities into programs written using that language. A great example of how secure-by-design principles are implemented in OCaml is its type and memory safety, which prevents the most frequent kinds of attacks and crashes from ever happening.

Memory-safety attacks are extremely common, with approximately 70% of zero-day attacks being memory-safety attacks. OCaml is memory safe because it doesn’t allow a pointer (the designator of the information being written into memory) to enter information into an unauthorised memory block. As a result, you can’t make a program crash with OCaml by manipulating where it writes code into memory, as OCaml simply does’t allow this to happen. This prevents programs crashing due to memory exploits, including buffer overflows, where memory is ‘tricked’ into writing more than the block ‘allows.’

OCaml is also statically-typed and type-safe, meaning that it detects errors at compile time and completely stops programs with defects from running, as well as limits what type of operations can be performed on which kinds of data. Both work to remove bugs and errors from the code, making programs written in OCaml more reliable and consistent.

The Takeaway : Cybersecurity is an increasing area of concern, and OCaml has several built-in features that help make it secure-by-design. It’s an excellent choice for projects where security is paramount.

5. OCaml is Big on Performance and Developer Productivity

OCaml is hailed for striking a balance between a large number of advanced features and performance. For example, it has a very efficient compiler that’s divided into two parts: a bytecode compiler and a native compiler. The bytecode compiler is very quick and generates small, portable executables. The native code compiler produces highly-efficient machine code.

Since OCaml also allows for some uses of imperative and object-oriented programming features, it’s possible to use them in places where they can help with performance. This flexibility of programming paradigms is another way that OCaml helps programmers increase the speed and efficiency of the code they write.

Type inference allows the language to infer what type is being used, removing the need for the developer to annotate every single variable in their code. This makes developing in OCaml faster than many other languages that lack type inference. OCaml also allows the developer to write complex algorithms without introducing bugs. The developer can easily optimise algorithms for greater speed without compromising performance and security. Furthermore, the presence and use of algebraic data types, higher order functions, and immutable data all make manipulating large and complex data structures much easier and faster.

It is also worth noting that OCaml offers several strong methods for debugging its programs. From the fast, interactive, REPL to the powerful symbolic replay debugger, OCaml lets you eliminate bugs at compile time and avoid them at runtime. This, in combination with how effective the debugging programs are, makes OCaml an easy language to debug. This saves developer time and increases the productivity and speed of programming.

The Takeaway : The OCaml language is strong on performance and has a lot of features that make the code run fast, while also making the development process more efficient.

6. OCaml is Multicore!

With the imminent release of OCaml 5, the language will support the use of multiple cores and have enhanced infrastructure in place for concurrent programming. Both bring significant performance boosts, allowing users to increase the speed of their programs.

The new I/O library Eio can serve more than one million requests per second, outperforming Go’s net/http and closely matching Rust’s hyper. Writing concurrent code will also be much easier in OCaml 5, just like writing regular OCaml. The ‘function colouring problem,’ whereby concurrent and non-concurrent code are incompatible, will also be a thing of the past after the new release. With OCaml 5, both kinds of code can coexist with minimal intervention on the part of the programmer.

Multicore or parallel programming increases the efficiency of a program by several orders of magnitude. By letting the computer use more than one core to execute the code, the program can do several things simultaneously rather than consecutively. For complex tasks that take a long time, Multicore revolutionises their applicability, making them more realistic and time-efficient alternatives.

You can look forward to more posts on the Tarides blog about OCaml 5, the technology behind it, and its use cases.

The Takeaway : OCaml 5 is coming, and with it, Multicore. OCaml will become even more powerful, both for parallel programming and concurrent programming, allowing users to significantly boost the speed of their projects.


Choosing the perfect programming language for you is an important but difficult task. It needs to be powerful and guarantee performance while simultaneously offering strong security features. Developers are also going to need state-of-the-art tools alongside responsive help and support. OCaml is a good candidate that offers all of the above, making it great for businesses looking for a versatile and robust programming language.

Combining the power of functional programming, Multicore, and open source, OCaml offers a potent mix of strong features and an engaged community. For more information about OCaml, you can visit the OCaml Website or contact Tarides to see how we can make OCaml work for you.