Ruby on Rails, released by David Heinemeier Hansson (DHH) in 2005, is an open-source web application framework known for "convention over configuration," with built-in ActiveRecord, MVC architecture, and a rich Gem ecosystem, a mainstream choice for building web apps efficiently.
Spree Commerce is an open-source e-commerce platform built on Ruby on Rails, released in 2007 with 13,000+ GitHub stars. Its API-first headless architecture suits Ruby teams needing deep customization and decoupled frontends.
Redmine is an open-source project management and issue tracking tool created by Jean-Philippe Lang in 2006, built with Ruby on Rails under GPLv2, supporting multiple projects, Gantt charts, time tracking, and 1000+ plugins, and completely free to self-host.