slim.js

slim.js is an opensource micro-framework for easy development of custom elements and/or applications, based on the Web Components v1 standard (fully supported).

It has a very low footprint (~5k gzipped) and is high-performant (compared to Polymer, VueJS, riot and many more).

It supports 1-way data binding, repeaters, native event deleagtion and it is extensible.

Both slim.js applications and slim.js standalone elements can be delivered with HTML imports or JavaScript.

The library also supports advanced features like decorators and typings and is easily bundled with tools like webpack.