Erlang
/ER-lang/ · noun · Development · Origin: 1986
Definitions
A functional programming language designed for building massively concurrent, fault-tolerant telecom systems. Erlang's 'let it crash' philosophy and lightweight process model enable systems with 99.9999999% uptime (nine nines). WhatsApp handled 2 billion users with a small Erlang team, and its VM (BEAM) is the foundation for Elixir.
In plain English: A programming language built for phone systems that never go down, designed so that if one part crashes, the rest keeps running.
Example: WhatsApp handled 900 million users with 50 engineers — that's the Erlang advantage.
Origin Story
Named after a Danish mathematician, but also a telecom pun
Joe Armstrong, Robert Virding, and Mike Williams designed Erlang at Ericsson's Computer Science Laboratory in 1986. They needed a language for programming telephone switches that could never go down -- reliability was the absolute priority.
The name **Erlang** serves double duty. It honors **Agner Krarup Erlang**, the Danish mathematician who invented queuing theory and teletraffic engineering. It's also a pun on **"Ericsson Language"** -- the telecom company where it was born.
Erlang's lightweight processes, pattern matching, and "let it crash" philosophy made it ideal for concurrent systems. When WhatsApp was handling 2 million connections per server with just 32 engineers, they were running Erlang. The language proves that niche tools built for specific constraints can achieve extraordinary results.
Coined by: Joe Armstrong, Robert Virding, Mike Williams
Context: Ericsson, Sweden, 1986
Fun fact: Ericsson briefly banned Erlang internally in 1998, which led Joe Armstrong to leave and the language to go open source. The ban backfired spectacularly -- open-sourcing Erlang made it more popular than ever.