pkgconfig 8.pc files

Hello...

Here goes a newbie type question. I have done a couple of installs of
RH8.0. On the first system (kernel to .18 and kernel modified) the
number of files in /usr/lib/pkgconfig with extension *.pc is 18. On the
second install the number of *.pc files are 58,right out of the 'box'.

I tried to install bubble on both, but on the first it couldnt find
libpanelapplet and libgtop. With the second install it cant find
libgtop. These files are there under /usr/lib.

(when I ./configure in the directory, the script reports that I should
add these missing libs to the *.pc)

How are these *.pc files generated? How do I properly configure the
libgtop.pc file? 

If this question is way off base let me know and I will go hunting 
for info again.

Andrew
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