Joost claims to have over 15,000 shows to view, with more being added every day. You need to download the player and sign up before you get started.
Joost also includes some social features and tools within the player, so you can chat while watching your video or view the latest news through a news feeder. The videos can be played on a full screen or re-sized to suit.
Miro is open source and provides 2,500 channels including a huge range of HD content (unlike Joost). In fact, Miro claims to be much better than Joost citing better access, features, content and organisation (comparison).
Download the Miro player and get started straight away. A quick search of Miro revealed over 300 channels tagged with 'education'.
Personally, I like both players and am quite happy to use both of them for different channels.
18/12/08 Update: As of Dec 19th 2008 the Joost software will be discontinued and all movies will be viewable on Joost.
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