Polymer lets you build encapsulated, reusable elements that work just like standard HTML elements, to use in building web applications. Developed by Polymer Authors
License: Open Source
Polymer is focused on creating reusable web components with a lightweight approach and adherence to web standards, making it suitable for standard-compliant applications. In contrast, React excels in building complex user interfaces with a rich ecosystem and strong community support, making it ideal for large-scale applications.