Personally, I cut my teeth on RoboHelp more than 20 years ago using it specifically for creating a Knowledge Base or Electronic Performance Support System (EPSS) used by a few hundred agents working in a customer contact center.
Is "first principles" some methodology or is it a company product?
I found RoboHelp to be very useful in the things I used it for. But I know that everyone has different requirements.
What are the specific aspects that are important to you?
For example, rapid access to information? RoboHelp has you covered there if you use it properly.
Centralized management of material? Again, RoboHelp shines in this area/
Commenting and "wikipedia" type of democratization and group management of information? RoboHelp may not be your thing for this as its model is more aligned with central publishing and mass consumption by users.
If we know more we can better direct you.
"First principles" is UK English for basics.
@Clair Rh is ideal for a Knowledge Base as the books be titled to show the knowledge areas and the topics can be the specific areas. The Employee Care sample project gives a basic idea. Click Open on the RoboHelp Starter page and then click Samples in the ribbon on the left.
The appearance can take advantage of newer skins that are included with RoboHelp and there are more free skins on Help Essentials provided by Willam van Weelden and Jonathan Smith.
I think I have also seen some pretty neat work created by yourself.
See www.grainge.org for RoboHelp and Authoring tips