Microsoft's decision to can its next generation WinFS file system has been described by Bill Gates as one of his biggest regrets



From The Inquirer:

Microsoft's WinFS was set to be one of the key technologies in Windows Vista but the next generation file system never saw the light of day, with Windows Vista sticking to NTFS. Gates, who was still very much involved with the firm at that time, cited WinFS as the one product that he wished Microsoft had shipped.

Gates made the comment during a Reddit question and answer session in which he described WinFS as, "a rich database as the client/cloud store that was part of a Windows release that was before its time. This is an idea that will re-emerge since your cloud store will be rich with schema rather than just a bunch of files and the client will be a partial replica of it with rich schema understanding."

  Bill Gates regrets that Microsoft didn't ship WinFS