Why this? Because this formats are free, and can be
played on the three major operating systems without
any doubt using the vlc projects video lan client.
So, we could easily take screen videos using xvidcap,
put them on the homepage and also offer the matching
pplayer (VLC) directly on the homepage to download.
So, spreading linux tutorial videos would be made easier.
What I still do not know is if the ffmpeg project has
meanwhile complete and not only experimental support