[wvenable]

> On submit, the first field that needs attention gets focused automatically

That is long solved.

> Error messages for semantic attributes are localized automatically by the browser

Assuming I want to use their error messages. I would prefer to provide my own, more detailed, error messages. Also what good is localized error messages in a non-localized form?

> The native message tooltip are actually nice and their placement is handled by the browser.

I definitely don't like the placement of the tooltip nor do I even like using tooltips for showing error messages. I much prefer permanently keeping the error message displayed under the field until the user edits the field.

I make some pretty large forms in my job with a lot of complex validation rules and non-technical users. We do validation way better than this.