Ruby 4.0.0 was released on December 25, 2025 and marked one of the most relevant updates to the language in recent years. The new version introduced Ruby Box, ZJIT, important performance improvements, advances in Ractor, and changes that directly affect developers building Ruby and Rails applications.
Ruby’s official documentation has been redesigned with the Aliki theme, bringing a more modern experience for reading, navigation, and search. The update improves day to day documentation usage and signals that ecosystem maturity also depends on developer experience, onboarding, and maintainability.