The videos here are in the patent-free Ogg Theora video format. This format is natively supported by Mozilla Firefox without any "plug-ins" or "extensions" necessary. If you're not already using Firefox for your Internet surfing, you really should. It's a free download.
Additionally, several standalone video players like VLC, MPlayer, and Xine support Ogg Theora playback. If you're running any GNU/Linux or BSD system, you are already golden.
The videos provided here are for informational purposes only. I do not assume any responsibility what-so-ever if you get hurt in any way from following what we do in these videos. Personal safety is your responsibility, so use this information at your own risk!