A post on the Official Gmail Blog has announced that Google Chrome and Chrome OS users can now automatically open mailto links within Gmail, all thanks to HTML5. Content handlers are the web's way of dealing with non-webpage data — be it mailto, webcal, or even magnet links — and the former has a bugbear for Gmail web users. Up until now, they've needed to either install an extension or carefully avoid using the links to prevent the operating system's default mail app loading. It's also worth noting that for Internet Explorer and Firefox users this is nothing new, and it comes a surprise that it has taken Chrome this long to implement the feature.
Next time you visit Gmail in Google Chrome, you'll be prompted by a bar at the top of the page to "Allow Gmail to open all email links," which will then associate the Gmail web interface with any email link. The content handlers also open up the potential for more web apps to integrate throughout Chrome, though for now there's no way to make Gmail the default mail app throughout your system without installing additional software.