Erlang OTP

Mainly aimed at server and embedded system development, Erlang is a multi-purpose runtime environment and programming language that can be used for a wide array of scalable applications.

With its built-in support for concurrency and fault tolerance, it's particularly useful for telephony and other telecommunication systems, instant messaging, banking, and e-commerce applications. It can also be used for database apps that require soft real-time behavior, as well as for creating servers for web apps.

It's worth highlighting the fact that this runtime environment includes powerful components for network systems, such as a Simple Network Management Protocol, an HTTP server, an OAM subsystem, a Common Object Request Broker Architecture interface, and a distributed database engine.

Even though it's allegedly easier to learn when compared to C++ or Java, first-time Erlang users should definitely take a look at the thorough documentation section found on the official website. The Getting Started section is of particular interest as it provides a few useful "hello world" examples and tutorials. http://erlang.org/faq/getting_started.html#idp31894096 http://erlang.org/faq/introduction.html

Even though it's not exactly the most popular programming language out there, Erlang proves its worth by its adoption rates by some of the largest companies out there. For instance, it's being used by Yahoo! for their social bookmarking service, by Facebook to power their chat engine's backend section, by WhatsApp for running messaging servers, and by Erricson for their support nodes.