Fewer than 500 words...
And now we have Flash's death certificate...
A dirty little secret known to those of us who do troubleshooting work is that Adobe's Flash plug-in has long been one of the least well-behaved pieces of "required" software for users. Users insist on having it so they can use content spread far and wide on the web, but it has never been particularly stable, it's a tremendous resource hog (hear the fans spin up on your laptop while you're browsing the web and you can be sure you just landed on a site heavily using Flash content) and there are continued issues with security vulnerabilities. However, it's a deeply entrenched technology, used for everything from coding websites to online games and videos, etc.
When Apple was teetering on the edge of survival it needed to keep Adobe happy, and so Macs shipped with the Flash plug-in installed for many years. Then Apple quietly stopped including it. Finally, with the advent of iOS, the iPhone and iPad Steve Jobs announced in April of 2010 that there would be no Flash support in iOS, and Flash would not be allowed on the platform. HTML 5 would be the only acceptable method of delivering the rich media content that Flash had had a lock on. Jobs went so far as to publish his reasoning in an open letter, Thoughts on Flash.