Kino: A high-performance Ractor web server for Ruby 4.0
Summary
Kino is a high-performance Ractor-based web server for Ruby 4.0+ that uses a Rust front end and Rack 3 compatibility to run apps in parallel within a single process. It offers multiple modes (:ractor, :threaded, and :auto) with benchmarks indicating strong throughput and memory advantages over Puma in various scenarios, though Rails remains not yet compatible with Ractor mode. The project is open source on GitHub with installation, configuration, and benchmarking details.