Wireless Application Protocol
At least part of this is a sort of down-trimmed HTML for the display of websites on the display of mobile phones and similar devices.
WAP is political, and therefore constantly on the verge of collapse, in a way distinct from HTTP, SMTP, HTML, and so on. In blunt language, WAP is tied more closely to telecommunications companies' "business models" than to customers' needs or engineers' vision. At least, that's a criticism made of it by apparently neutral observers.