In macOS Sierra, Safari 10 will simply ignore Flash in favor of HTML5

Flash -- despite the best efforts of many -- is not quite dead. It continues to hang around like a festering scab, just waiting to be cast off forever. With macOS Sierra, Apple is playing its part in consigning Flash to the history books, pushing HTML5 to the fore.

Following in the footsteps of Google Chrome, starting with Sierra, Apple's Safari will ignore Flash even if the legacy plugin is installed. HTML5 will be favored for each and every site -- a marked difference from Chrome which maintains a list of exceptions (such as YouTube) which could still make use of Flash.

Apple says that Safari will simply turn a blind eye to the fact that Flash is installed. "When Safari 10 ships this fall, by default, Safari will behave as though common legacy plug-ins on users' Macs are not installed". Of course there will be some sites that really do need Flash, and despite Apple's seemingly hard line, this does not mean that those that are slow to embrace HTML5 will be inaccessible:

In a blog post for developers, the company says:

On websites that offer both Flash and HTML5 implementations of content, Safari users will now always experience the modern HTML5 implementation, delivering improved performance and battery life. This policy and its benefits apply equally to all websites; Safari has no built-in list of exceptions. If a website really does require a legacy plug-in, users can explicitly activate it on that website.

Apple's new policy means that Safari, essentially, lies to websites about which plugins are installed. It no longer passes on information about the availability of Flash, Java, Silverlight, and QuickTime, encouraging the browser to switch to HTML5. If this is not possible, users will be given the option of enabling Flash on a one-off basis, or every time they visit the site in question.

Could this finally be the death of Flash?