Q:

categorize browser JavaScript API's

in the web browser there is available lots of JavaScript web API's
all of those are listed in here(Firefox browser web API list page)
https://developer.mozilla.org/en/docs/Web/API
in here list is going very long....
are these API's not categorized in any where?
if then we can  identify which feature are available in web browser easily among those big long list of API's.

A:

You are looking for Modernizr. It's a script that detects a definable selection of HTML5/CSS3 features in the browser, and then exposes them both to CSS via classes on the HTML element and Javascript via the Modernizr object. It also has an interactive API.
The list of supported features is at the bottom of the help page, and follow logical categorization as you require.

