For many years, the internet has been plagued by a dependency on the proprietary software known as Adobe Flash. There are plenty of open alternatives that could be used, but from the beginnings of the internet, ShockWave and Flash have been used by many websites.
Flash has been used for everything from buttons and banners to games and complete user interfaces. It’s a very powerful tool, but it is outdated and is maintained exclusively by Adobe. While the Flash player browser plugin is completely free, the tools to create Flash content are not. There in lies the trouble. Being closed source, Flash depends on Adobe development. There are many people who use 64-bit Linux as their primary OS. Adobe has canceled development on the 64-bit version of there Flash plugin. This means that simple things like Youtube videos won’t work on 64bit Linux.
This is why proprietary formats are bad. Hopefully things will improve as more and more webmasters turn to HTML5, CSS3, and Javascript for their Dynamic content needs.