OCaml

vs

Crystal

Haskell is a free and open-source purely-functional programming language. The language has been around since the 1990's and has pioneered a number of advanced programming language features such as type classes, which enable type-safe operator overloading. Haskell is an open-source project of more than twenty years of scientific research and provides built-in concurrency and parallelism, debuggers, profilers and rich libraries that can be used to build robust applications while following functional programming patterns.

A dynamic, functional programming language that tuns on top of the Erlang Virtual Machine. A VM known for running low-latency, distributed and fault-tolerant systems. Elixir provides productive tooling and an extensible design perfect for building concurrent applications for critical infrastructure

A general-purpose, concurrent, functional programming language used to build massively scalable soft real-time systems with requirements on high availability. Erlang comes bundled with the OTP, the Open Telecom Platform which is a runtime system first developed by Ericsson to handle the Swedish telecom infrastructure in the early 80's. The term Erlang and OTP is today used interchangeably and includes the runtime, the language and ready-to-use components built specifically for the ecosystem. To this day, Erlang is used in various sectors and applications like telecoms, banking, e-commerce, computer telephony and instant messaging. As the language is suitable for critical infrastructure and applications that requires high availability and real-time features, running at scale.

An object-oriented, high-level, general-purpose programming language with an easy-to-learn syntax. Python was first released in 1991 by Guido van Rossum with a design philosophy that emphasises code readability. Today Python is one of the most widely used programming languages where it is used in everything from data science, machine learning and AI to modern web, mobile and desktop applications.

Ruby is a free and open-source interpreted, high-level, general-purpose programming language. The language was created by Yukihiro "Matz" Matsumoto from Japan in the mid-1990s. Today, Ruby has a friendly and growing community from all over the world and is openly developed and maintained. According to its creator Yukihiro, the language share many similarities with Perl, Smalltalk, Eiffel, Ada, Basic, and Lisp, all of which Ruby was influenced by.

ClojureScript is a compiler for Clojure that targets JavaScript. It emits JavaScript code which is compatible with the advanced compilation mode of the Google Closure optimizing compiler. With ClojureScript, you write browser and web-based applications using Clojure and the REPL, allowing you to write the same Lisp syntax that you are used to in the Clojure ecosystem.