RUBY 4.0.0 RELEASED

Summary from the TLDR newsletter

Ruby 4.0 introduces Ruby Box and ZJIT and adds many improvements. Ruby Box is a feature that provides separations about definitions. Definitions loaded in a box are isolated in the box. ZJIT is a new just-in-time compiler developed to raise the performance ceiling and encourage more outside contributions. It is faster than the interpreter, but not yet as fast as YJIT.