Brian, since you seem to have gone through the process of upgrading KDE by
compiling your own binaries, you seem a logical person to ask:

How do you know what you need to install in order to be able to compile
something?

When I set up my Mandrake workstation(s), I de-selected all of the
Development tools because I am NOT a developer or coder.

I originally did pretty much the same in the less-advanced install programs
for an early RedHat distribution, and was completely turned off of trying to
compile software because every time I tried it was an unding string of
unresolved dependencies, and I could never figure out how to install ENOUGH
to be able to compile anything.  Since then, I've been shackled to RPM
installations.

I also know that if you start crossing RedHat and Mandrake RPMs, you can
seriously hose your system.

Are you really safe taking, say, the generic Ximian sources and compiling
them for Mandrake 8.1?

Since disk space isn't the problem it was a few years ago, I suppose I could
just use the RPM manager in Mandrake and blindly install every package that
even LOOKS like it might be a source of development package, but there
should be a better way.