If you go to the "Impartial" page (https://www.thistothat.com/impartial.shtml) there's a little "Best viewed in any browser" gif. Sadly given the proliferation of Chrome-only web apps, those things really need to make a come back.
What bothers me is that if you build from the ground up, you already get all of that for free.
Use semantic HTML elements, write your content, then you snazz it up with CSS and JS if you want. It will work everywhere, in every accessibility tool, with no extra work whatsoever.
