Out for Christmas is Ruby 3.3 as a big update to this dynamic open-source programming language. With Ruby 3.3 the Prism parser is added as well as a new pure-Ruby just-in-time (JIT) compiler.
Ruby 3.3 brings with it the Prism parser as a portable, error-tolerant, and maintainable recursive descent parser. Prism is considered production-ready and can be used now in place of the Ripper parser.
Ruby 3.3 also adds RJIT as a pure-Ruby compiler to replace MJIT. Right now though RJIT only supports x86_64 on Unix-like architectures and is considered for experimental purposes only.
While RJIT is interesting, it's not yet production ready and users are recommended to use the YJIT compiler still. YJIT with this Ruby 3.3 release has received many performance improvements, significantly improved memory usage, and a variety of other enhancements to make this JIT compiler much better than with prior releases.
Ruby 3.3 also goes on to use Lrama as the parser generation to replace Bison, the M:N thread scheduler was introduced, and there are a variety of other performance improvements such as to Ruby's garbage collector.
Downloads and more details on this big Christmas update with Ruby 3.3 can be found via Ruby-Lang.org.