Follow the links and be prepared to have your mind moderately blown.
Learn You Some Erlang is a free online tutorial website dedicated to teaching the Erlang programming language. The site offers a comprehensive, in-depth guide to Erlang, presented in a friendly and accessible manner. It's designed to take readers from beginner to advanced levels, covering both theoretical concepts and practical applications.
Erlang is a functional programming language with a focus on concurrency and distributed systems. Originally developed by Ericsson for telecommunications applications, Erlang has gained popularity in building scalable and fault-tolerant systems. The language features built-in support for concurrent processes, message passing, and hot code swapping, making it ideal for developing robust, high-availability applications.