Well, ini files (which, from the example, I guess is what you mean when you say “system config files”) are not exactly an evolving thing… So if the libs worked when they were written, I guess there is no reason why they shouldn’t be still working today, and if they were reasonably feature-complete, there is no reason why anything should be changed.
However, AFAIK ini files are not really standardized in any way, and several different flavors exist. So you will have to try out whether or not a library can handle the ini flavor you have in mind the way you want.