I think for OP case, Firefox is not supported based on some specific
HTML5 feature. Each browser has some amount of HTML5 support. Question
is which feature the app is using, that determines whether browser
supports it or not.
If you go to this site with browser:
http://html5test.com/, you'll see
that not any browser scores perfect points, so each has some limits in
HTML5 support.
And it will also vary by Firefox version as well. The lower versions
(e.g. FF 3.6) has some support but less than the recent versions.
And while on this topic, I learned that WebDriver may not have HTML5
support for certain features as well. So even if browser support is
there, you might not be able to automate it yet. For example: HTML5
uploader that supports multiple file uploads is partially workable in
WebDriver, that is you can upload 1 file at a time, can't do multiple,
or at least I haven't figured out how to do so.
> Tried the sitehttp://www.toyotapriusprojects.comand it works like any