Reason lets you write simple, fast and quality type safe code while leveraging both the JavaScript & OCaml ecosystems. Reason is not a new language; it's a new syntax and toolchain powered by the battle-tested language, OCaml. Reason gives OCaml a familiar syntax geared toward JavaScript programmers, and caters to the existing NPM/Yarn workflow folks already know.

Single-spa is a javascript framework for front-end microservices. Use multiple frameworks in a single-page application, allowing you to split code by functionality and have Angular, React, Vue.js, etc. apps all living in harmony.

As CSSNext is now deprecated you can use instead the Postcss plugin "PostCSS Preset Env" to lets you use modern CSS in your style sheet.