Rubyspeed - "Right now, Rubyspeed is a basic proof of concept (horribly hacked together) that allows annotating method declarations to automatically be specialized and compiled to C."
The beauty of LiveView - If I was going to move to a new platform at this point, it would likely be Elixir plus Phoenix.
BriskBard - All in one browser, email and RSS client, IRC, media player and more.
Diffend - "OSS supply chain security and management platform for Ruby applications."
Headless Recorder - "Headless recorder is a Chrome extension that records your browser interactions and generates a Puppeteer or Playwright script."