See e.g. Dendron.
I see Dendron adds hierarchy by using naming conventions. That doesn't appeal to me at all, smacks of the Dewey decimal system, and ultimately everything ending up in '999miscellaneous', or the alt. usenet category. Whereas to me, as per Weinberger, everything starts as misc and its place in the scheme of things is emergent.
2 Elsewhere in the garden
Notes that link to this note (AKA backlinks).