Erlang/OTP 21.3 is the third service release containing mostly bug fixes and characteristics improvements but also a few features.

OTP 21.3 Readme File

OTP 21.3 Source File (90347905)

OTP 21.3 Windows 32-bit Binary File (90347905)

OTP 21.3 Windows 64-bit Binary File (92618042)

OTP 21.3 HTML Documentation File (33069226)

OTP 21.3 Man Pages File (1332545)

OTP 21.3

Erlang/OTP 21.3 is the third service release for version 21 release with, improvements as well as a few features!



  • The standard logger handler, logger_std_h, now has a new internal feature for log rotation. For full information see the documentation.


  • The Reason part of the error return from the functions connect and handshake has a better and documented format. This is a potential incompatibility. See the documentation.
  • Refactoring of state handling has improved the TLS application data throughput and reduced CPU overhead
  • Code optimizations has reduced CPU load for encryption/decryption, especially for Erlang's distribution protocol over TLS
  • Now supports active N


  • Support for plugin of a user supplied socket implementation has been added.


  • The HTML reference documentation now shows the OTP version where modules and functions were first introduced.
  • Versions of OTP older than R13B04 is not shown in the reference documentation

For a full list of details see:

Pre built versions for Windows can be fetched here:

Online documentation can be browsed here:

The Erlang/OTP source can also be found at GitHub on the official Erlang repository, Here: OTP-21.2

Please report any new issues via Erlang/OTPs public issue tracker

We want to thank all of those who sent us patches, suggestions and bug
Thank you!
The Erlang/OTP Team at Ericsson

Compiling Erlang from source

You can build Erlang from source on your own, following the building and installation instructions. Or use the Kerl script. Kerl is a script that lets you easily build Erlang with a few commands. Follow the instructions to build.

Finding a source version

Follow this link that presents all released source versions, a link to the GitHub source tag, and to the README.

Pre-built Binary Packages

Most OS package managers provide pre-built binary packages. You can also download the latest stable releases from Erlang Solutions. Erlang Solutions provides pre-built binary packages for OS X, Windows, Ubuntu, Debian, Fedora, CentOS, Raspbian and other operating systems. 

  • For Homebrew on OS X: brew install erlang
  • For MacPorts on OS X: port install erlang
  • For Ubuntu and Debianapt-get install erlang
  • For Fedorayum install erlang
  • For FreeBSDpkg install erlang


Since OTP 18.0, Erlang/OTP is released under Apache License 2.0. The older releases prior to 18.0 were released under Erlang Public License (EPL), a derivative work of the Mozilla Public License (MPL).