I'm looking for recommendations for a structured help platform.

By that I mean a tool by which a broad range of staff can create,
edit, inter-link, classify and maintain a set of structured
documentation for fixing problems and resolving issues.

Open source, closed source and hosted solutions considered, but the
platform must enforce structure (i.e. not a wiki); do LDAP / SAML /
etc; decent reporting of high-use docs; and be easy to use for
literate non-techies.

It seems like there should be a drupal module or something for this,
but for the life of me I can't see it (but then there are a confusing

Pointers to accounts of other people doing similar things also readily accepted.

...let us be heard from red core to black sky