Haskell vs Erlang

Are you an aspiring programmer looking for a new language to learn? Do the languages Haskell and Erlang spark your interest?

When it comes to learning powerful, modern programming languages, there are few better choices than Haskell, with its traditional roots and general-purpose capabilities by way of pure functional programming; or Erlang, which excels in developing distributed applications within many types of distributed environments.

Here is a difference table comparing Haskell and Erlang:

Programming paradigmFunctional, lazy evaluationFunctional, concurrent, message-passing
Type systemStatic, strong, inferredDynamic, strong
Main use casesAcademic research, mathematics, domain-specific languages, web servicesTelecommunications, distributed systems, fault-tolerant systems, real-time applications
Concurrency modelLightweight threads (green threads), software transactional memory (STM)Lightweight processes, message-passing concurrency
SyntaxCompact, expressive, mathematicalProlog-inspired, pattern matching
PerformanceGenerally good, with some performance trade-offs due to lazy evaluationDesigned for low latency and real-time responsiveness, well-suited for concurrent applications
Error handlingStrong type system, monads for handling errors and side effects“Let it crash” philosophy, process supervision, hot code swapping
Community & EcosystemStrong academic community, niche industry usagePrimarily used in telecom and related industries, some web development
ImplementationsGHC (Glasgow Haskell Compiler)Erlang/OTP (Open Telecom Platform)
Notable librariesLens, Yesod, Servant, Pandoc, QuickCheckCowboy, Mnesia, Riak Core, RabbitMQ

Difference between Haskell and Erlang

Programming paradigm

The programming paradigm of a language can be an important factor when deciding which language to use for a particular project.

Haskell is a purely functional language that makes use of lazy evaluation, allowing expressions to only be evaluated when needed.

On the other hand, Erlang features a strong focus on concurrency and message-passing which allows it to create highly concurrent systems with fault-tolerance capabilities.

Knowing the different characteristics of these two prominent programming paradigms can help developers make an informed decision about their project’s development environment.

Type system

While both Haskell and Erlang have strong type systems that help ensure the correctness of code, their approaches differ significantly.

Haskell’s static type system is able to infer types at compile-time allowing for better control over errors.

On the other hand, Erlang’s dynamic type system offers more flexibility in programming as it does not perform strict compile-time checks.

However, this flexibility comes with a cost as errors can easily slip through in the form of runtime crashes. Both languages have their respective advantages when it comes to typed programming and choosing between them ultimately depends upon the specific requirements of your use case.

Main use cases

Haskell is used most often for use cases such as academic research, mathematics, domain-specific languages, and web services while Erlang has a tradition of use in industries like telecommunications, distributed systems, and real-time applications.

No matter the purpose, these two languages are highly appreciated for their capabilities when correctly applied.

Concurrency model

As such, many programming languages have adopted a specific model for managing concurrent operations. Haskell has chosen lightweight threads and software transactional memory (STM), while Erlang has opted for lightweight processes and message-passing concurrency.

Both of these techniques can yield high levels of performance, allowing code to coexist peacefully with other processes. By utilizing these models, programmers can build powerful systems without having to worry about clashes or other issues that can arise from having multiple operations running concurrently.


At a glance, the syntax of Haskell and Erlang might seem quite different. However, both languages have syntax that is designed to make programming easier.

Haskell’s syntax is compact, expressive, and even has elements of mathematics embedded within it; this approach makes understanding code simpler and allows ambitious projects to be tackled using its concise syntax.

Meanwhile, the syntactical structure of Erlang draws inspiration from Prolog, with an emphasis on pattern matching for improved data processing capabilities.

Through innovative syntax design in both languages, developers are empowered to construct code that can take advantage of powerful solutions without sacrificing readability or scalability.


Haskell is well optimized for performance, allowing developers to write efficient code without needing to worry about the specifics of optimizing. Its main tradeoff comes in its approach to lazy evaluation, which delays data processing until the results of a computation are actually needed – an approach that can lead to slower program execution under some circumstances.

On the other hand, Erlang’s focus on low latency and real-time responsiveness make it a great choice for concurrent applications and high availability systems. Its design centers around keeping latency short and predictable rather than achieving maximum performance through optimization.

Error handling

Haskell takes advantage of its strong type system and monads to isolate and contain errors as they come up, thereby protecting the rest of the program from an irrecoverable crash.

Erlang, on the other hand, utilizes a somewhat drastically different strategy by utilizing “let it crash” philosophy – encouraging processes to continuously attempt to catch errors while using process supervision and hot code swapping to replace faulting processes with newer versions when errors occur. This ensures that any issue is isolated in a segment without compromising functionality or data integrity within the wider application.

Community and ecosystem

Haskell is used in academia to study and develop new ideas, while the industry applications have found their own niche with incredible success.

Erlang has grown rapidly within the telecommunications industry, and is beginning to gain traction in web development as well. This says a lot about how both Haskell and Erlang have established their respective roles within the wider development ecosystem.

Both Programming languages bring something special to the table, providing tools for developers to create amazing products.

Examples of Use Cases for Both Languages

Comparing the uses of both languages can be an interesting task. For example, Java is often used for creating web applications with a focus on functionality. It is also commonly used to create desktop GUI applications and many applets run in JVMs.

On the other hand, Python can be applied to many different domains like scientific computing, machine learning, and artificial intelligence projects. It is perfect for scripting and automating tasks or as a powerful interactive programming language used to debug new code. Both languages have their own strengths, making them popular in various development scenarios.


Ultimately, Haskell and Erlang are two distinct languages that serve different use cases. While Haskell is better suited to complex applications requiring precise control over functional programming and type theory, Erlang shines with its robust concurrency and distributed programming model.

On the other hand, compared to Haskell’s complex syntax, Erlang’s flexibility and readability can offer rapid application development at the expense of some performance gains.

Finally, in terms of community and ecosystem, both these languages have strong followings flocking around them in areas such as academia or industry due to their different strengths and limitations. No matter which language programmers decide to pursue for their development needs, both these languages will continue to shape the future of software development for years to come.