browser-plugin-gnash binary package in Ubuntu Xenial amd64

 GNU Gnash is a free GPL'd SWF player. It runs as a standalone application
 on either the desktop or embedded devices, or may be used as a plugin
 for several popular browsers. It supports playing media from a disk or
 streaming over a network connection.
 .
 GNU Gnash is based on GameSWF and supports most SWF v7 features and some
 SWF v8 and v9. SWF v10 is not supported by GNU Gnash.
 .
 Included in the Gnash is an XML based messaging system, as specified in
 the SWF specification. This lets a SWF animation communicate over a TCP/IP
 socket, and parse the incoming XML message. This lets an animation be a remote
 control for other devices or applications.
 .
 This package includes the plugin for Firefox/Mozilla Web Browser. The plugin
 works best with Firefox 1.0.4 or newer, and should work in any Mozilla based
 browser.

Source package