Breaking Changes to the Web Platform

Over the years there have been necessary changes to the web platform that caused legacy websites to break.

Below is a list of those changes.

• SSL removed in favor of TLS wiki
• Adobe Flash (SWF) End of Life wiki
• <applet> and <marquee> and many other tags removed html5
• window.showModalDialog removed operablog
• Passive touch listeners by default googleblog
• Forms with passwords marked Not Secure over HTTP googleblog
• Array.prototype.flatten breaks MooTools bugzilla renamed to Array.prototype.flat
• HTML Imports (part of Web Components) deprecated googleblog
• Cookies changed from SameSite=None to SameSite=Lax by default chromestatus tweet
• alert() and confirm() removed from cross-origin iframes chromestatus tweet