Clarion (http://softvelocity.com).
I could/can get a demo banged together for a project like this in a matter of hours.
One perspective deficiency is that it creates Win32 executables. Of course, this can be solved by creating a web system with it.
Another is that Clarion is definitely not open source. Which would put a lot of folk off.
Okay. My last comment was about 2 hours ago. So in that time, here's what I managed to get done in Clarion.
http://125.214.67.190:5824/
I'm not writing this to brag. I honestly believe Clarion can do amazing things in a very short period of time.
The "Knowledge" system is very much a demo. You can only add Tags and Relations to the parent Nodes. There isn't a proper Tag/Relation search (only singular). No images or decent graphic design or UI.
But the framework, the foundation is there.
