We use MediaWiki + SMW / Semantic Forms. This allows to define a data model and forms which makes it easy for user to add / write to the wiki in a structured way - and without sitting before a blank page. For free text, the new Visual Editor works also rather well, though it's not easy to setup.

The structured information can also be queried, visualized, exported to various data formets etc.

To document software projects, I really like to write *executable documentation". E.g. I'm using JSON Schema a lot to define my expected data structures and contracts between modules.

Then I write a small program that automatically generates the technical documentation based for me. Humans can still add/annotate to the documentation because it's a wiki (and I can separate between auto-generated and human-generated rather easily, because of queries).

So far, I really like this approach as it has the automation of doc generators, the flexibility of wikis. Most of the information is stored/accessible as data / API. The downside of this appraoch is, that this platform takes some time and knowledge to setup and model the data structure / forms. Without those, corporate wikis usually seem to die the "one man show" death you described