Erlang/OTP 18.1 is a service release on the 18 track with mostly bug fixes, but is does contain a number of new features and characteristics improvements as well.

Some highlights of the release are:

  • ssl: Add possibility to downgrade an SSL/TLS connection to a tcp connection, and give back the socket control to a user process.
  • ssh: The following new key exchange algorithms are implemented:'ecdh-sha2-nistp256', 'ecdh-sha2-nistp384', 'ecdh-sha2-nistp521','diffie-hellman-group14-sha1', 'diffie-hellman-group-exchange-sha1' and 'diffie-hellman-group-exchange-sha256'. This raises the security level considerably.
  • kernel,stdlib,sasl: A mechanism for limiting the amount of text that the built-in error logger events will produce has been introduced. It is useful for limiting both the size of log files and the CPU time used to produce them. 
    This mechanism is experimental in the sense that it may be changed based on feedback. See config parameter error_logger_format_depth in the Kernel application.


You can find the Release Notes with more detailed info at

You can download the full source distribution from

Note: To unpack the TAR archive you need a GNU TAR compatible program. For installation instructions please read the README that is part of the distribution.

You can also find the source code at in the official Erlang repository. Git tag OTP-18.1

The Windows binary distributions can be downloaded from

You can also download the complete HTML documentation or the Unix manual files

You can also read the documentation on-line here: 
(see the Release Notes mentioned above for release notes which 
are not updated in the doc, but the new functionality is)

We also want to thank those that sent us patches, suggestions and bug reports.

The Erlang/OTP Team at Ericsson