Features that we enjoy today, thanks to the browsers we hate today.

What have been some CSS and JS features that IE or Edge has pushed forward?

I know both get a bad wrap, but I've also heard that some of the things we constantly use today are thanks to Microsoft's browsers implementing them first.

Hoping we can make an extensive list of those features/APIs.

If you can, please also link a ref/spec link in the comments and I'll be sure to do some more background work (to describe the feature and its history when possible) and I'll be sure to update this post.

Thanks 🤓