• Enhanced IO scalability
• compact instructions on 64bit systems for code below 4GB 20% less memory for loaded code
• Rewrite of the efile-driver with NIFs and "Dirty schedulers" resulting in faster file operations
• non-smp VM removed
• link and monitor optimized for scalability
• os:getenv/putenv now work on thread-safe emulation. No longer in sync with libc getenv(3). Manual synchronization will be needed.
• Misc compiler optimizations including contributions from the Elixir team resulting in 10% improvements in benchmarks
• "Tuple calls" have been removed from the run-time system.
• More information in stacktrace from a number of operators
• erlang:get_stacktrace/0 deprecated to be replaced with try ... catch C:R:Stacktrace -> ...
• Creation of small maps with literal keys optimized.
• A new predifined macro OTP_RELEASE and preprocessor directives -if and -elif
• DTLS is now supported in the SSL application
• Enhanced support for distribution over TLS
• "unsecure" ciphers removed from defaults in SSL and SSH.
• A new option value defined to facilitate implementing exec servers. Old option kept for compatibility, but now gives errors on stderror.
• New API for logging, logger
• New uri_string module for parsing URIs according to "The standard"
• New function lists:search(list,fun/1) -> {ok, Value} | false
• Changed default behaviour of .erlang loading. escript, erlc, dialyzer and typer no longer load an .erlang at all.

Full release notes

• Installed
• Rebuild elixir
• Tested phoenix project
• Opened observer