Flash Player
Flash was officially discontinued by Adobe. You can still intsall an executable version of Flash Player to play saved Flash files offline.
Flash Player is was an essential plugin for any graphic-enabled Web Browser. In fact, most content on this site is in the Flash format, and requires the newest version of Flash.
Not only animations, but whole sites have been designed to be viewed with Flash Player. I cannot stress how essential upgrading this plugin is for your Web Browsing experience.
Be sure to have the Flash Player plugin installed for all your Web browsers. If you download a new browser, you must reinstall Flash Player for it to take effect in the new browser.