Riot
Simple and elegant component-based UI library
...It is designed to offer you everything you wished native the web components API looked like. HTML syntax is the de facto language of the web and it’s designed for building user interfaces. The syntax is explicit, nesting is inherent to the language, and attributes offer a clean way to provide options for custom tags. Minimalism sets Riot.js apart from others. One of the design goals was to introduce a powerful tag syntax with as little boilerplate as possible. Riot.js has between 10 and 100 times fewer API methods than other UI libraries.