Details of Node.js 21’s new features, including ES modules default, WebSocket client, test runner enhancements, and more — Node.js major release is rolled out every six months. The new release becomes the Current release for six months, which gives library authors time to add support for them. After six months, odd-numbered releases, such as 21, become unsupported, and even-numbered releases, such as 20, move to the Active LTS…