In previous versions of NodeJS / Browser JavaScript, you would have used "callbacks". Which leads to <a href="http://callbackhell.com/" class="external-link" target="_blank">callback hell</a>.

## Coroutines

    * This was reported internally by [@rushilsrivastava](https://github.com/rushilsrivastava) as a memory leak when the server had unhandled exceptions that would produce internal server errors, the memory allocated before that point would not be released.