WAP Proof is a professional WAP browser intended for developers of mobile content. WAP Proof supports WML, XHTML-MP and mobile-oriented HTML. Several mobile devices (Motorola, Nokia, Sagem, Siemens, Sony Ericsson) are emulated, so you can open your site with your favorite mobile browser and switch between different mobile devices by few mouse clicks. The WML card or XHTML page is rendered exactly as if you were downloaded it on the real cell phone. Besides the rendered card, the source code of the document may be viewed. WAP Proof works over HTTP like an usual HTML browser and has the most of its features, such as using bookmarks, changing the document encoding, working offline. The following features are particularly useful for mobile content designers: XML syntax validation, XML syntax highlighting, tolerance to XML errors, viewing entities as characters, logging of the HTTP traffic, modification of HTTP headers, direct access to the HTTP query, modification of POST requests, viewing WML context variables, control over WML events. The HTTP request entity is similar to that of a real WAP browser, so you can develop an user-agent specific site. Additional HTTP attributes, for instance, the attribute containing MSISDN, may be easily added to the request.