The Wireless Application Protocol (WAP), which includes Wireless Markup Language (WML) and a Binary XML Content Specification, has been receiving a lot of discussion on the XML-dev mailing list recently.

WAP support is already available from vendors (Phone.com, Motorola, Ericsson, Nokia, Sprint) and many cell-phone manufacturers have either begun building these features into new products or announced plans to do so. WAP itself was developed in the WAP Forum, a consortium of wireless vendors.

Not everyone is delighted with WAP and its many components, however. Rohit Khare's W* Effect Considered Harmful, examined the protocol stack of WAP 1.1 and found problems with every layer. Khare's analysis rejects the exceptionalism of the wireless vendors and calls for standards more consistent with existing Internet and Web protocols.

Amazon.com reports that Official Wireless Application Protocol is popular in both Sweden (home of Ericsson) and at Motorola.

• Update: PC Magazine has an article on WML and handheld computers and cell phones.
• Motorola has released a Mobile Application Development Kit for WAP.