"Providing flash access means people can get instant gratification by watching the videos there and then. The videos are also freely downloadable, so you are not restricted to using the Google flash player to watch them. Fact is most people have flash installed and so it's easy for them to watch the videos. Ease of use and a low barrier to entry are important to this project."
In addition to which, every screencast is also available in OGG/Vorbis/Theora format.
The player is, yes.
From the FAQ:-
"Providing flash access means people can get instant gratification by watching the videos there and then. The videos are also freely downloadable, so you are not restricted to using the Google flash player to watch them. Fact is most people have flash installed and so it's easy for them to watch the videos. Ease of use and a low barrier to entry are important to this project."
In addition to which, every screencast is also available in OGG/Vorbis/Theora format.