The internet and web design is ever evolving. If you were around computers and the internet back in the late 1990s or early 2000s, safe to say that the way we used to design websites is very different from today. This also means the evolution of the tools that we use to create websites, and by the end of 2016, Mozilla plans to drop support for a number of said tools in its Firefox browser.
According to a post on the Mozilla blog, “Mozilla intends to remove support for most NPAPI plugins in Firefox by the end of 2016. Firefox began this process several years ago with manual plugin activation, allowing users to activate plugins only when they were necessary. This decision mirrors actions by other modern browsers, such as Google Chrome and Microsoft Edge, which have already removed support for legacy plugins.”
What this means for users is that if the websites that you visit still rely heavily on Java and Silverlight plugins (for example), chances are by the end of 2016 they may not render properly in the Firefox browser, meaning that you will need to use a different one if you wish to access it. That being said the end of 2016 means that web designers and developers still have more than a year to start incorporating new tools in their websites, so hopefully by then this will be a non-issue.