Erlang

Erlang is a functional programming language and runtime environment (known as OTP - Open Telecom Platform) built by Ericsson. Its entire design is centered on “massive concurrency” and “high availability.” It achieves this by using lightweight, isolated processes (not OS threads) that communicate via messages (the “Actor Model”). This “let it crash” philosophy allows for the creation of fault-tolerant systems where failures in one part do not bring down the entire application, making it ideal for telecom (its original use), messaging (like RabbitMQ), and other distributed, high-availability backend systems.