In an effort to encourage developers to use HTML5, the new Safari 10, which will come with the new macOS Sierra, disables any plug-ins like Flash, Java, QuickTime, and Silverlight by default. Apple has stated that if a website offers content in both HTML5 and Flash, the browser will automatically display the site using HTML5. Should the website require a plug-in like Silverlight to work at all, the user will be prompted to use the software one time, just during that session, or every time she visits that specific website.
Apple’s move seems to be not only a step towards a better web browsing experience in general, but one that aims to increase their users’ safety while browsing. For example, Java and Flash have been quite problematic for Apple for a long time, requiring frequent fixes and updates that, more often than not, create more system vulnerabilities than resolve any bugs.