The Ruby programming language version 4.0.0 is expected to be released at Christmas, as per tradition. It includes:
- YJIT Enhancements: The existing YJIT compiler continues to receive optimizations, including compressed context to reduce memory usage and better register allocation for variables and arguments.
- ZJIT: Ruby 4.0 introduces ZJIT (Zuckerberg JIT) as a new experimental method-based JIT compiler, alongside the existing YJIT. ZJIT is still in early development and not yet ready for performance evaluation but represents a key area of focus for the release.
- Core Primitives in Ruby: More core primitives, such as Array#each, Array#select, and Array#map, are being rewritten in Ruby for better performance when YJIT is enabled.
- Concurrency and Parallelism: Enhancements to the experimental Ractors (Ruby Actors) model to make writing concurrent code more stable, performant, and usable, bringing them closer to non-experimental status.