How does normalize.html function?

There is not much to worry about here. Basically it's just giving all of the elements a default and mostly blank set up. It's normalizing how all of the different block elements are rendered, how all of the inline elements are rendered, and normalizing how they are all rendered across browsers.

It's so you have to write less browser specific code to make you elements more consistent among browsers, and it allows frees up some time for you.

For me, it's a set it and forget it. You can make whatever changes you want to it. My suggestion for that is to take advantage of CSS cascading effect, meaning I'd first include normalize.css and than, I would include my own style sheet after that, and all of my edits and overrides would go in that style sheet. Since my style sheet is second in the source order, it would override any conflicting styles from normalize.css.

As far as who maintains it. We'll its basically open source, so it's community driven. If you were to attribute an author to it, Nicholas Gallagher is the name that comes up, and the offical Github page recongizes Jonathan Neal as a co-creater. There are currently 13 contributors to normalize.css, but anybody with a Github account could make a merge request that could eventually be added to normalize.css

https://github.com/necolas/normalize.css/