This article explains how to handle and recover from errors reported by XML parsers. It presumes a fundamental grasp of XML Syntax, and an understanding of object models generally and the DOM (Document Object Model) specifically.
When debugging XML documents, it is important to remember that XML parsers are strict. They complain for errors that an HTML browser would silently ignore.
This was a design goal for the development of XML. It was decided that HTML had grown too difficult to implement because the browsers were too lenient. According to some estimate, more than 50 percent of the code in a browser deals with correcting errors.
That's a huge burden on the browser developers and it may explain why competition in the browser space is limited.
Furthermore, XML has been designed with a wide range of computing platforms in mind. This includes full blown desktop but it also includes smaller devices (portable phones, PDAs like the Palm Pilot, and so on). These devices lack the memory and power to recover from complex errors.