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Erlang is a powerful and reliable language for developing distributed systems. It has strong support for concurrency, fault tolerance, and hot code swapping. Erlang is also widely used in many industries and applications, ranging from telecoms to banking and e-commerce. Erlang is an open source, distributed, general-purpose programming language that was originally developed in 1986 by Ericsson. It is used for building robust, fault-tolerant, low-latency applications. Its primary design goals are scalability and concurrency, both of which it achieves through its lightweight processes and message passing system. Erlang has been successfully used in a number of high-demand applications including telecoms, banking, e-commerce, computer telephony, and web development.

Introduction to Erlang

Erlang is a general-purpose, concurrent, functional programming language, and a garbage-collected runtime system. It was originally developed by Ericsson as a proprietary language to be used for telecommunications applications. It was released as open source in 1998 and has since become one of the most popular languages for developing distributed systems.

Erlang has its own virtual machine, the Erlang Virtual Machine (EVM), which builds on the functionality of the conventional virtual machine by adding support for message passing, soft real-time garbage collection, and multi-threading. The language also features high scalability, fault tolerance and hot code loading.

The language can be used in many different contexts, including web services, distributed applications, telecommunication, and gaming. It is also popular for use in areas such as artificial intelligence and natural language processing.

Erlang is a general-purpose programming language and concurrent runtime environment used in many applications and industries. It was originally developed by Ericsson in 1987 and released as open source in 1998. The language is best known for its low-level abstractions, scalability, fault-tolerance, distributed processing capabilities, and real-time performance. It is often used in telecoms, finance, gaming, and ecommerce applications.

History of Erlang

Erlang was developed in 1986 by Joe Armstrong at the Ericsson Computer Science Laboratory. Originally, it was used for programming telephone switching systems, such as AXE (the first commercial system to run the new software).

In 1998, Ericsson released Erlang as open source software. The language quickly gained interest from developers, especially those looking for fault tolerance, scalability, and performance when building large-scale applications.

Since then it has been used by organizations such as WhatsApp, Amazon, Facebook, and the BBC. In 2018, Erlang was accepted into the Code Mesh conference as an official language.

Erlang is a general-purpose functional programming language created by Joe Armstrong and Robert Virding in 1986. It has gained a lot of attention in recent years, due to its ability to construct highly performant distributed systems. Erlang has been used in telecoms, banking, e-commerce, industrial control, and many other sectors.


Erlang was originally created as a language for creating telecommunications software. Joe Armstrong, one of the creators of Erlang, was working for Ericsson in Stockholm. Armstrong and his team wanted to create a language that could easily be adapted to different types of telecommunications equipment and protocols. The resulting language was Erlang.

The language was designed to be reliable and fault-tolerant. This meant that a system written in Erlang would be able to withstand any single point of failure and still continue to operate. This made it an ideal choice for developing telecoms software.

Features of Erlang

Erlang is known for its scalability, fault tolerance, and concurrency. The language has a number of features that make it ideal for creating reliable, distributed systems.


Erlang provides processes that are isolated from each other, allowing programs to be written as sets of processes that communicate with each other. This means that multiple complex operations can be running in parallel, making Erlang ideal for distributed systems.

Fault Tolerance

Erlang has built-in error detection and crash recovery mechanisms, making it well-suited to creating fault-tolerant applications.


Erlang allows for distributed applications to scale easily. It uses a distributed process model to allow for efficient scaling to hundreds or even thousands of nodes.

Erlang Use Cases

Erlang is widely used in many different contexts, ranging from web services to gaming. Here are some of the use cases:

Web Services

Erlang is used by several major web services, such as WhatsApp, Amazon, and Facebook. It is well-suited for handling large numbers of simultaneous connections, as well as providing high availability.


Erlang was initially developed for use in the telecommunications industry. Its features make it well-suited for applications such as call routing, billing systems, and messaging platforms.


Erlang is used in the development of online games. Its scalability and fault tolerance make it a great choice for creating online gaming platforms that can support thousands of players.

Artificial Intelligence

Erlang is used in artificial intelligence applications, such as natural language processing. Its support for concurrency makes it well-suited for tasks such as language translation and speech recognition.


Erlang offers many features that make it an attractive language for many developers.

One of the most notable features of Erlang is its support for concurrent programming. Erlang supports lightweight process threads, which can run in parallel without interfering with each other. This makes it much easier to develop programs that can take advantage of multiple CPU cores.

Erlang also has strong error handling capabilities. When an error occurs, the process is stopped and restarted from a checkpoint. This allows for rapid debugging and prevents errors from cascading through a system.

Erlang also supports hot code swapping. This allows changes to be made to a system while it is running. This reduces the amount of time spent on testing and debugging, as well as reducing the time needed to make changes to a system.

Finally, Erlang has a robust set of libraries for creating distributed systems. These libraries allow developers to create powerful and reliable distributed systems, such as those found in telecoms and banking applications.

Erlang is a concurrent, functional language designed to support soft real-time, distributed applications. It has a wide range of powerful features that make it ideal for developing apps that require scalability and reliability, as outlined below:

  • The language has built-in support for soft real-time applications, allowing developers to constrain the resources that an application can use.
  • It enables distributed computing, which allows tasks to be partitioned into separate nodes running on different computers across a network.
  • It supports hot code loading, allowing developers to instantly update an application without having to restart it.
  • Erlang has built-in support for fault tolerance, providing developers with mechanisms to detect, isolate, and repair errors quickly.
  • It offers asynchronous message communication and non-block process communication, which helps to ensure scalability and reliability.
  • It is a garbage collected language, which means it reclaims unused memory automatically, reducing the need for manual memory management.


Erlang has many advantages over other programming languages. These include:

  • Fault tolerance - Erlang has a unique message-passing architecture that allows it to gracefully recover from unexpected failures. This makes it particularly suited for distributed systems and critical applications where downtime or data loss needs to be minimized.

  • Fast development - Erlang is a high-level language that allows for fast development. It also comes with an extensive library of pre-built functions and modules that can be reused and customized for specific projects.

  • Flexible and extensible - Erlang can be extended with C and C++ libraries, making it extremely flexible and allowing developers to build on top of existing code.

  • Scalable - Erlang is designed from the ground up to be highly scalable. There are no hard limits on how many concurrent processes can be running on an Erlang system, making it incredibly powerful for distributed applications.

Usage Examples

Erlang is used in a variety of applications and industries. Some of the most notable examples include:

  • WhatsApp - WhatsApp is one of the world’s most popular messaging apps, and it is powered by a backend written in Erlang. By leveraging the language’s unique characteristics, WhatsApp has been able to quickly scale its platform to serve millions of users.

  • RabbitMQ - RabbitMQ is an open source message broker that is used in distributed systems as an intermediary between different services. It is built entirely in Erlang, allowing it to take advantage of the language’s fault-tolerance while delivering high performance.

  • eCommerce - Erlang is a popular choice for eCommerce platforms due to its scalability and low latency. It is used in some of the biggest online stores worldwide, such as Amazon and eBay.

Code Examples

Here is a simple example of how to compile and run an Erlang program:


main() ->
  io:fwrite("Hello, World!~n").

To run the program, type:

$ erlc hello_world.erl 
$ erl -run hello_world main
Hello, World!

This example will print “Hello, World!” to the console.

Erlang has been successfully used in a number of high-performance applications. Here are few examples:

  • Telecom Systems: Erlang is used in building telecom system software, including telecom switching, mobile networks, and soft switches.
  • Banking Applications: Erlang is commonly used to build banking applications such as ATMs and payment processing systems.
  • E-Commerce: Erlang is used to power e-commerce applications such as those run by Amazon, eBay, and PayPal.
  • Computer Telephony: Erlang is used to power computer telephony applications such as VoiceXML and IVRs.

Here are few examples of code written in Erlang.

The following example shows how to create a function that adds two numbers:

add_numbers(X, Y) ->
    X + Y.

The following example shows how to spawn an Erlang process:

spawn(F, A) -> 
   spawn(fun() -> F(A) end).

And here is an example of a program that implements a basic chat server:



start() ->
    Pid = self(), 
    gen_server:start({local, ?MODULE}, ?MODULE, [Pid], []).

handle_call(_Request, _From, State) ->
    {reply, ok, State}.

handle_cast({message, From, Msg}, State) ->
    io:format("~p says ~p~n", [From, Msg]),
    {noreply, State}.


Erlang is a powerful, general-purpose programming language with a unique set of features that make it ideal for distributed, fault-tolerant, and real-time applications. It is used in a wide variety of industries and is becoming increasingly popular due to its versatility, scalability, and ease of development.

April 20, 2021 by