> For the complete documentation index, see [llms.txt](https://cpb.gitbook.io/book/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cpb.gitbook.io/book/languages/erlang/history.md).

# History

## Meaning of 'Erlang'

The name *Erlang* was given in honor of the first scientist in the field of telecommunications: **Agner Krarup Erlang (1878-1929)**

Sometimes the name of language is also interpreted as **Er**icsson + *Lang*uage = **Er\***lang\*.

## In Ericsson lab

**Between 1982 and 1986**, in Ericsson labs were conducting research on the suitability of some existing programming languages in terms of creating apps for **telecommunications** needs, which required **long-lasting** and **trouble-free operation with a large number of threads**. The features of each language were analyzed, identyfiying potential problems that they could have caused. Despite the gradual narrowing of the set of considered languages, it was established that **none** of them meet the company's requirements, therefore it was decided to design a **completely new language from scratch**.

## Long story in short

The author of the language is **Joe Armstrong**. He modeled Erlang on the **Prolog language** and wrote first Erlang interpreter in it. In **1990**, Erlang was shown publicly at the **ISS '90 conference**, which resulted in increased number of users. But the first implementation of the language was so inefficent that in the **late 1980s** itself, work began on a faster version. **It's final release took place in 1991**. **A Year later**, the first book about Erlang was published and in **1993**, Ericsson launched an independent department assigned with the development and distribution of the system and tools for it.

In **1998**, Ericsson launched **AXD301** switch with software that contained a milion lines of code in Erlang, which achieved a reliability index of **99.9999999%** (that's the real number!), which meant that in a year of usage, the system could have **at most 0.0315 seconds of downtime due to a failure**. Shortly thereafter, Ericsson banned its affiliates from using Erlang in new products due to its proprietary nature. **This caused a conflict between Ericsson and Armstrong, who left the company with the team.** **At the end of the same year**, the Erlang implementation code was **opened sourced and made available as free software**. The ban was withdrawn later and **Armstrong** returned to work with Ericsson in **2004**.