Facebook, as well as most of the code out there, is still using CommonJS, since there are very real issues with ES6 modules that are still unresolved[1]<p>[1] <a href="https:&#x2F;&#x2F;twitter.com&#x2F;sebmck&#x2F;status&#x2F;692443162804092928" rel="nofollow">https:&#x2F;&#x2F;twitter.com&#x2F;sebmck&#x2F;status&#x2F;692443162804092928</a>