We are pleased to announce the release of Ruby 2.3.0.

This is the first stable release of the Ruby 2.3 series.
It introduces many new features, for example:

A [frozen string literal pragma](https://bugs.ruby-lang.org/issues/11473)
is introduced.
With Ruby 2.1, `"str".freeze` has been optimized to reduce object allocation.
Ruby 2.3 introduces a new magic comment and command line option to
freeze all string literals in the source files.
Additionally for debugging, you can get where the object is created on
`"can't modify frozen String"` error by using the
`--debug=frozen-string-literal` command line option.

A [safe navigation operator](https://bugs.ruby-lang.org/issues/11537)
([so-called lonely operator](https://instagram.com/p/-M9l6mRPLR/)) `&.`,
which already exists in C#, Groovy, and Swift, is introduced to ease
`nil` handling as `obj&.foo`. `Array#dig` and `Hash#dig` are also added.
Note that this behaves like [try! of Active Support](http://api.rubyonrails.org/v4.2.5/classes/Object.html#method-i-try-21),
which specially handles only `nil`.

The [did_you_mean gem is bundled](https://bugs.ruby-lang.org/issues/11252).
The did_you_mean gem
shows the candidates on the `NameError` and `NoMethodError` to ease
debugging.

[RubyVM::InstructionSequence#to_binary and .load_from_binary](https://bugs.ruby-lang.org/issues/11788) are introduced as experimental features. With these features, we can make a ISeq (bytecode) pre-compilation system.

Ruby 2.3 also includes many performance improvements, for example
[reconsidering method entry data structure](https://bugs.ruby-lang.org/issues/11278),
[introducing new table data structure](https://bugs.ruby-lang.org/issues/11420),
[optimizing Proc#call](https://bugs.ruby-lang.org/issues/11569),
machine code level tuning for object allocation and method calling code,
[smarter instance variable data structure](https://bugs.ruby-lang.org/issues/11170),
[`exception: false` keyword argument support on Socket#*_nonblock methods](https://bugs.ruby-lang.org/issues/11229),
and so on. Check the "Implementation improvements" section in the NEWS file.

For a complete list of new features and compatibility notes, please see
[NEWS](https://github.com/ruby/ruby/blob/v2_3_0/NEWS) and
[ChangeLog](https://github.com/ruby/ruby/blob/v2_3_0/ChangeLog).

With those changes, [2946 files changed, 104057 insertions(+), 59478 deletions(-)](https://github.com/ruby/ruby/compare/v2_2_0...v2_3_0) since Ruby 2.2.0!

Merry Christmas, Happy Holidays, and enjoy programming with Ruby 2.3!

## Download

* <https://cache.ruby-lang.org/pub/ruby/2.3/ruby-2.3.0.tar.bz2>

      SIZE:   14185617 bytes
      SHA1:   6c8a832d49d22755ea8c45b6d53faf2ccc6d6ac9
      SHA256: ec7579eaba2e4c402a089dbc86c98e5f1f62507880fd800b9b34ca30166bfa5e
      SHA512: 77b707359e754c3616699d21697752741497c719dc3d6fdfb55ed639e76d52560d293ae54cbe5c63be78dc73fbe60f1b8615d704d017bdfe1994aa9747d26a6c

* <https://cache.ruby-lang.org/pub/ruby/2.3/ruby-2.3.0.tar.gz>

      SIZE:   17648682 bytes
      SHA1:   2dfcf7f33bda4078efca30ae28cb89cd0e36ddc4
      SHA256: ba5ba60e5f1aa21b4ef8e9bf35b9ddb57286cb546aac4b5a28c71f459467e507
      SHA512: 914d0201ecefaeb67aca0531146d2e89900833d8d2a597ec8a19be94529ab6b4be367f9b0cee2868b407288896cc14b64d96150223cac0aef8aafc46fc3dd7cc

* <https://cache.ruby-lang.org/pub/ruby/2.3/ruby-2.3.0.tar.xz>

      SIZE:   11294412 bytes
      SHA1:   96e620e38af351c8da63e40cfe217ec79f912ba1
      SHA256: 70125af0cfd7048e813a5eecab3676249582bfb65cfd57b868c3595f966e4097
      SHA512: d893c5e6db5a0533e0da48d899c619964388852ef90e7d1b92a4363d5f189cd2dba32a009581f62b9f42a8e6027975fc3c18b64faf356f5e3ac43a8d69ec5327

* <https://cache.ruby-lang.org/pub/ruby/2.3/ruby-2.3.0.zip>

      SIZE:   19840511 bytes
      SHA1:   3f88617568d9a4f491e8b32dca532363f73eaa71
      SHA256: 8270bdcbc6b62a18fdf1b75bd28d5d6fc0fc26b9bd778d422393a1b98006020a
      SHA512: a3f397bb3c9c19d9b797552c5d60bb01c82db884cfa966df84881125bea35713cffd99f88fb86b271bae72d9cfb09ad9b33838cffcf6365c091459479914fdef