When you have much more than one line of these "a=b", that sugar helps. XML has hierarchy, you can group related values into elements. XML has comments. XML can be typed, the standard even defines formats for numbers, date and time. There're good libraries to serialize/deserialize objects to XML, from pretty much all OO languages out there. I use them a lot, and I rarely expect users to edit XML, I give them GUI to change the settings they need, updating the config.