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A paneled view from MacOSX file browser
|A view from Blackboard
It seems that Blackboard looks more like the way Sakai used to be, with 'add' buttons at the top in the actions bar, rather than by the folders, and no tree view. I notice that they've called WebDav 'Web Folder' - interesting in view of the debates that there have been lately about renaming it to make it intentionally more obscure, rather than less!
Slightly different - but a view from Flickr showing all files (here, images) along the bottom of the screen, with the 'folders' (here, sets) at the top