The plugins we use in our browsers are a holdover from an earlier time. They provide handy features not built into the browsers. But, plugins also provide a varied collection of problems. The problems are enough of a pain that Firefox, Google, and other browser publishers are going to remove support for them.
Firefox has a list of the plugins that cause problems for their browser. See: Firefox Blocked Plugins. But, it is not just certain plugins that are going to be blocked. We are talking support for all plugins. Firefox will start by blocking all plugins as their default behavior.
Google will be blocking all but a few plugins. Flash, Silverlight, and Unity plugins have Google’s blessing. But, by the end of 2014 even those will be blocked and eventually support removed. By May Google will be refusing to allow new apps or updates to apps in their App Store. See: Google Will Start Blocking Most Netscape Plug-In API Plug-Ins In January 2014.
What Are Some Plugins?
Flash is a ubiquitous plugin that nearly every person has installed. It is mandatory to play Facebook games. But, Flash is going away. My web design tools have lots of new tools to use for creating web apps that are not plugins.