What is Gnash?
Gnash is the GNU flash movie player, which can be run standalone on the desktop or an embedded device, as well as as a plugin for several browsers. Gnash is based on GameSWF, and supports most SWF v7 features and some SWF v8 and v9.
The project seems to be no longer developed. Last version, 0.8.10, released in February 2012, can be still downloaded from Git.