Why doesn xAP use XML?
One of the main design goals for xAP was a fast, light weight implementation – both in terms of network utilisation and device processing power. The flexible structure of XML is comparatively difficult to parse, and XML messages are prone to bloat. In contrast, the xAP wire format is essentially untyped (or rather, it is implicitly typed), and the structure constrained, which allows for very light parsers which are able to operate at lightning speed with a minimum of resources.
