DeviceAtlas tells you if XHTML-MP is supported with three properties, one for every version of XHTML-MP. If you wanted to go with an easy approach you can simply use the reference to XHTML-MP 1.0, the property name is markup.xhtmlMp10.

We do not provide information about WML, though, so you can't check a property for that. If you checked and XHTML-MP or Basic (we have that information too) and consider sending WML, you might want to check the Accept header. If you are using PHP you will find the information in $_SERVER['HTTP_ACCEPT'], I would do something like this:

if (strstr($_SERVER['HTTP_ACCEPT'], 'text/vnd.wap.wml') !== false ) {
// print WML markup
}

Thanks Andrea - we''ll probably direct traffic to WML site if

1) User Agent is unmatched i.e. device not recognised (maybe a few years old/no longer in production)
or
2) XHTML-MP 1.1 or XHTML-MP 1.2 are not supported.

Hopefully that should ensure users without newer browsers have a better user experience via WAP

Cheers,
Ciarán

Ciarán,
I recommend that you extend case 2 adding XHTML-MP 1.0 and XHTML Basic.

XHTML Basic is probably the safest choice today in Europe and US as it covers all WAP 2 devices, Blackberries, iPhones, Windows mobiles, etc.

So Andrea, what you are saying is:
When you start developing a new mobile site now, implement it in XHTML-MP 1.0 and then you cover 99% of the currently used devices.
Pieter

It depends which countries you are targeting, to be honest. If you target is Europe and US you can be very confident XHTML Basic and XHTML-MP will work. If you look at developing countries, it can vary, in India they sell a lot of cheap phones, but they are new if you look at the technology, in the sense that maybe you will not find many Nokia N95 or iPhones, but a lot of Nokia series 30 and 40 that are perfectly capable of displaying XHTML pages.

Some countries like China have some barriers that will not let you detect the device, so it is in fact impossible to know if it will really work and there, probably WML is still safer.

Definitely we should be aiming for a unique markup, that will make the life of developers and designers easier and, to be honest, also brings consolidation in the browser engines world which should be good for device manufacturers.