Those are two of the exceptions to the rule. Quite literally; there is a section of the Mozilla browser codebase that actively seeks out those plugins (along w

Those are two of the exceptions to the rule. Quite literally; there is a section of the Mozilla browser codebase that actively seeks out those plugins (along with QuickTime, Windows Media Player, and Acrobat Reader) because users who lack them experience a "broken web" (http://lxr.mozilla.org/mozilla-central/source/dom/plugins/base/nsPluginDirServiceProvider.cpp http://lxr.mozilla.org/mozilla-central/source/dom/plugins/ba...). I'm not saying becoming one of those plugins is impossible---clearly, it's been done more than zero times. I'm saying that I really wouldn't base any business decisions around the assumption that it will happen for your plugin.