I have an asciidoc based chain that mostly works for generating both PDF manuals and standalone html docs but it's a bit of a faff to install and set up especially for non-technical users.
My dream is something like pandoc but with one or more diagram libraries integrated, native PDF output and all wrapped up in a single binary, maybe with a nice web UI/editor built into the binary. Oh, and if it could manage multiple documents and versioning that would be great too. Looking for a Fossil SCM kind of feel?
Closest thing I've used would probably be LyX but that's almost too capable!
I do appreciate this is a really hard thing to do and I'm wondering what toolchains other people are using?