Gnash is the GNU SWF player.
Gnash supports playback of AVM1 Flash movies, with most of the important functionality implemented. Gnash supports many video sites, games, and other Flash utilities.
Gnash runs on GNU/Linux, Haiku, AmigaOS, Hurd, the BSDs, and Windows, including on embedded systems.
Gnash is fully customizable and supports the download and saving of all loaded and streamed content, automated screenshots, and rendering of SWF to audio and video files.
Gnash does not have support for AVM2, the new Virtual Machine used for ActionScript 3 and found in many version 9 and 10 SWF files.