What exactly is this window?

[revmacian]

I have noticed that, in many KDE apps, you can press the F1 key and get help with the app - this is also available from the app menu Help > $APPNAME handbook. This pops up a new window with the handbook for that app. What exactly is that window (handbook). This window looks suspiciously like the .chm files I used to compile when I was on Microsoft Windows years ago. See the attachment for an example of the KPatience handbook.

What I'm thinking:
Can I write new documents that appear in that window? Is that a WebView module that simply displays html files in iframes? I'm thinking that, if I can learn how to do this, I can write personal documents with the exact same layout and view them on my desktop. I'm already proficient with writing html and CSS files, so it seems it would be easy enough to write my own documents and have them appear in a window like that. So, what exactly is that window and how do I write personal documents to appear in that window?

[claydoh]

The KDE/Plasma doc files are docbook xml files, which the Khelpcenter tool converts to html for viewing.
They are stored in /usr/share/doc/HTML/<Language>/,application name>

I imagine one could create custom documents, following the same formatting.

As the Help tool also shows UNIX man pages and the like, there probably other ways as well, though I am not sure how.
It seems that creating the docbook formatted help file mimicking the file and content structure of an existing application's help file would be enough.
I am probably wrong though.

[Snowhog]

I am probably wrong though.

How can an American, posing as a Kangaroo riding a Fixie, ever be wrong?

[revmacian]

The KDE/Plasma doc files are docbook xml files, which the Khelpcenter tool converts to html for viewing.
They are stored in /usr/share/doc/HTML/<Language>/,application name>

I imagine one could create custom documents, following the same formatting.

As the Help tool also shows UNIX man pages and the like, there probably other ways as well, though I am not sure how.
It seems that creating the docbook formatted help file mimicking the file and content structure of an existing application's help file would be enough.
I am probably wrong though.

Thank you, claydoh! Well, my mind likes to simply things so I may just write my documents in html/css and view them in a web browser. Since the Khelpcenter tool converts the docbook files into html for viewing anyway, there is no real need to learn docbook format when I already know how to write html/css files. I use Visual Studio Code and it has plugins for html and css so I think I'll just stick with that. But, Khelpcenter is a nice tool and I learned something new today.

Thanks again!