If you're like myself and forget over time what some of the more uncommonly used equality operators actually do under the hood, this resource is great for getting a quick explanation of the functionality and a general level of support across browsers.

Simply type in the operator you'd like an explanation for such as the nullish-coalescing operator (??) to get an immediate result. You can also select an operator from the list under the search if you're not immediately sure which operator you're looking for.

A great write-up about optimizing a set of functions spread across a handful of popular JS libraries in a reasonably straightforward way to understand and replicate in the packages you know and use on a daily basis.