Ruby 4.0 released

Once again there is a brand-new release under the tree from the
Ruby programming-language project: Ruby 4.0
has been released with many new features and improvements. Notable
changes include the experimental Ruby Box
feature for in-process isolation of classes and modules, a new
just-in-time compiler called ZJIT, and improvements to Ruby's
parallel-execution mechanism (Ractor). There are a number of language
changes as well. See the documentation
for Ruby 4.0 for more.