We are pleased to announce the release of Ruby 4.0.0.Ruby 4.0 introduces “Ruby Box” and “ZJIT”, and adds many improvements.

Ruby is a dynamic, object-oriented programming language known for its simplicity and elegance, offering a productive and enjoyable development experience for software engineers. Developers can learn about Ruby programming fundamentals, web development with Ruby on Rails, and building scalable and maintainable applications with Ruby's expressive syntax and rich ecosystem of libraries and frameworks.

Ruby

Ruby 4.0.0 has been released with two major experimental features: Ruby Box for isolating definitions (useful for monkey patches and parallel deployments) and ZJIT, a new JIT compiler that's faster than the interpreter but not yet production-ready. The release includes significant Ractor improvements for better parallelism, promotes Set and Pathname to core classes, adds new methods like Array#rfind and Math.log1p, and introduces Ractor::Port for inter-Ractor communication. Performance enhancements include faster Class#new, improved GC, and reduced lock contention. Breaking changes include removal of several deprecated Ractor methods and process creation via pipe syntax.

Ruby 4.0.0 Released