1 changed 0x64 in binary option encoding of all atoms from ATOM_EXT to ATOM_UTF8_EXT and SMALL_ATOM_UTF8_EXT. This is now changed so that only atoms actually containing unicode characters are encoded with the UTF8 tags while other atoms are encoded ATOM_EXT just as before.
1 with scheduler_wall_time now also includes info about dirty CPU schedulers. The new purge strategy introduced in OTP 19. The NIF library reload is not supported anymore. Atoms can now contain arbitrary unicode characters which means that the DFLAG_UTF8_ATOMS capability in the distribution protocol must be supported if an OTP 20 node should accept the connection with another node or library. Third party libraries which uses the distribution protocol need to be updated with this. Erlang literals are no longer copied when sending messages. Warnings for repeated identical map keys.
By default there is now a warning when export_all is used. Atoms may now contain arbitrary unicode characters. 2 has an option to include extra chunks in the BEAM file. 2 has been added to dict, orddict, and gb_trees. Most OS package managers provide pre-built binary packages.
The older releases prior to 18. PDF files are included in the Windows installer and in the HTML documentation tarballs, starting with the R13B03 release. There is a file containing MD5 checksums for all files in the download directory, also reachable through rsync rsync. This is a game I created on Tinkercad Circuits to learn binary numbers.