As I understand it, xanadu's goal is to interstitch documents, in a similar manner (I just realized) to git blame; documents are composed of original text, and

As I understand it, xanadu's goal is to interstitch documents, in a similar manner (I just realized) to git blame; documents are composed of original text, and pieces of other documents, recursively. So you can traverse the history not just of the document, but the blocks of text as they get referenced and pointed to by newer documents. I can't remember though if those blocks were meant to be updated as the original does, or if they're treated immutably. This on the other hand has a much simpler goal: organizing your documents into a tree. Afaict, it can be treated/navigated like a file system, except that theres no distinction between file and directory.