Polymer is a new type of library for the web, designed to leverage the existing browser infrastructure to provide the encapsulation and extendability currently only available in JS libraries. Polymer is based on a set of future technologies, including Shadow DOM, Custom Elements and Model Driven Views. Currently these technologies are implemented as polyfills or shims, but as browsers adopt these features natively, the platform code that drives Polymer evacipates, leaving only the value-adds.
Polymer is a tool in the Frameworks category of a tech stack.
What are some alternatives to Polymer?
Bootstrap is the most popular HTML, CSS, and JS framework for developing responsive, mobile first projects on the web.
Material Design is a specification for a unified system of visual, motion, and interaction design that adapts across different devices. Our goal is to deliver a lean, lightweight set of AngularJS-native UI elements that implement the material design system for use in Angular SPAs.
It is a bunch of cool, fun, and cross-browser animations for you to use in your projects. Great for emphasis, home pages, sliders, and general just-add-water-awesomeness.
Tailwind is different from frameworks like Bootstrap, Foundation, or Bulma in that it's not a UI kit. It doesn't have a default theme, and there are no build-in UI components. It comes with a menu of predesigned widgets to build your site with, but doesn't impose design decisions that are difficult to undo.
Material UI is a library of React UI components that implements Google's Material Design.