A recent security "fix" for Adobe Flash causes it to consistently crash Firefox, so I decided to try one of the competitors: swfdec and gnash. I used to simply not install Flash, but I watch enough videos on YouTube these days to find that undesireable now (although I'd much prefer YouTube switch to a non-proprietary format, I'm not holding my breath).

swfdec is kind of nice in that it doesn't automatically start playing. This is a great feature as I consider most Flash content to represent major suckage. If I'm not watching a movie then I don't really need the modern equivalent of an animated GIF wasting my time.

Anyway, swfdec seems to work well, at least in my limited testing (youtube). One site I found that didn't work was voodoopc.com, which happens to work under gnash. Given that, I'm using gnash for the time being, but I consider them both viable as neither of them has crashed Firefox yet.

They both also nicely eliminate the very last bit of non-open source software from my laptop. If you're running Linux, I highly recommend you try one of these alternate players.