Brent Simmons and Manton Reece:
For most developers, JSON is far easier to read and write than XML. Developers may groan at picking up an XML parser, but decoding JSON is often just a single line of code.
Beyond developer advantages, one of the really nice things about JSON is that it’s very nearly human-readable, even in code form. Take a look at my JSON feed — the most unreadable parts of it are the raw HTML blocks; everything else is pretty self-explanatory.