ruby Ruby on Rails is being used as a full-stack application to build a video conferencing platform with Vonage Video Express and UI Toolkit Vivid. The platform allows users to create watch parties, join existing ones, and share screens. It also includes features like moderator controls, participant muting, and audio input selection. The application uses the "Convention Over Configuration" philosophy of Rails and leverages the strengths of both frameworks to provide a robust and scalable solution. With this tutorial, developers can build their own video conferencing platform using Ruby on Rails and Vonage Video Express.