The whole directory structure is filled from sql data. And all those relationships they showed in the video are just different row and column joins from the file metadata in SQL presented through the virtual file system driver for WinFS. That's how I understand
it, and I may be wrong.
On linux you can also provide "fake" directory listings and file listings to a client of the fs driver, so you could do the same thing.
Not exactly. There are two manners of accessing data in WinFS. One is via the Win32 CreateFile/OpenFile APIs (and their managed counterparts). These APIs allow you to double-click files within WinFS and have them open in Word, Photoshop, etc. However, this
API only gives you what you get in Win32... file streams.
However, we have built a set of managed APIs that expose WinFS data as CLR objects with relationships, etc. This API is what the applications you saw (LifeJournal, StoreSpy) work against to create and navigate relationships.