reading xml

I have heard many places that XML is a good way to store certain data. But, I always make and use my own "markup script"; so I was thinking, the only way that it would be easier was if there was an already existing XML file reader.
Does anyone know of a XML library/class/reader that I could use?

Ah, I found one.

Now I found an ever better one; iirXML.
I had no idea they where called parsers.

Popular ones are libxml2, expat and Xerces-C++.