&gt; Just look at the many open source JS libraries out in the wild–how many of them use prototype objects well? If they use OOP, it’s usually class-based, and it’s pretty ugly, too.<p>Worth mentioning some that do use prototype objects, such as Closure Library <a href="https:&#x2F;&#x2F;github.com&#x2F;google&#x2F;closure-library" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;google&#x2F;closure-library</a>