4+ help systems

I'm trying to get my parents switched to Linux, but I can't come up with 
any rational explanation of why there are 4 different help systems.

man, info, kde, gnome.

There is no utility that can browse/search all these systems (at least 
"man -k" style).  If you don't know the name of the thing that you 
don't know, then you are just stuck.  If it isn't in a menu someplace, 
then you often have no idea that gnome/kde provides an app to do X.

The info folks started creating simple man pages that show the very 
basics and then tell you to use info.  That's a good start.  If only 
kde/gnome would do something similar.

Then there are the docs under /usr/share/docs/mumble...  First, there 
should be a way to find out about these "extra" docs in the 
man/info/etc pages (if they exist).  Second, this is yet another help 
format, argh!  There is a good point here that you may need different 
types of documentations: reference, tutorial, overviews, license, etc.  
A lot of that gets done ad-hoc and put in share/doc.  But there needs 
to be some kind of master index and search program!

-Dan