It's browser vendors that are bearing the torch of interoperability and standards compliance. Unfortunately, most vendors are companies with their own agenda. To add to that, all companies and people interpret standards differently. Given this, it's no wonder we don't see consistent api implementation and behaviors between browsers.

The aftermath of all of this falls on the developer's shoulders, which is why so many hours are poured into getting a modern webapp to work across all browsers. Resources are limited, and at some point, developers have to throw their hands up and resign from having support across all browsers.

When you start using a seemingly mature HTML5 api, and find that it doesn't work as expected in all browsers, what recourse does one have? Should we continue to stifle innovation while we wait for the browser vendor to reach compliance? History shows you're going to be waiting for a while, or for ever.

"When you start using a seemingly mature HTML5 api, and find that it doesn't work as expected in all browsers, what recourse does one have?"

File bugs. Chromium and Firefox are not black boxes.

Very often the bugs have been filed by someone else. Years ago.

A few examples that come to mind:

https://code.google.com/p/chromium/issues/detail?id=67587

https://code.google.com/p/chromium/issues/detail?id=178297

https://bugs.webkit.org/show_bug.cgi?id=102914

or here's an opportunity to start contributing to open source!

One option is to ensure that functionality you're relying on can fall back if the feature isn't enabled. While that's not the hip-and-cool thing to do, it is a very valid option and doesn't take considerable time if it's a goal from the outset.