Bliss
Blissful JavaScript
...Bliss is just a collection of helpers and light syntactic sugar over Vanilla JS. It does not account for browser bugs or lack of support of certain APIs, although it only uses features that are both supported across most modern browsers and can be polyfilled. For example, it uses Promises throughout (supported by all latest browsers, can be polyfilled), but, despite the temptation, not arrow functions (syntactic extension, cannot be polyfilled). The idea is that you can extend support by using polyfills, depending on your needs.