What's different between HTML and WML/WAP?

Question

I checked the source of a few WAP sites,

but doesn't find anything different from a normal HTML page.

Can you name a few detailed points?

Myrna

Answer 1

Well, WAP/WML is very strict when it comes to markup because the page needs to be compiled before delivery to the client device.

As for specifics,

• WAP "pages" can have more than one "card". (Confusing? I know...)
• Although not markup related, accepted image formats are more limited
• Do not forget a DOCTYPE!
• Content must be served with the text/vnd.wap.wml MIME type

Gat

For spec 1,do you mean there can be multiple html tags? +1 for helpful info! – Myrna

Answer 2

WAP 1 has almost nothing in common with the HTML/CSS/JS/server-side-scripting stack. The only connection it has with the larger web is that telco gateways use HTTP to request WML content from a normal web server. WML is an old-fashioned and ugly ‘card’-based hypertext system which everyone hated, largely failed in the market and is long gone (thank goodness).

The misleadingly-named “WAP 2”, on the other hand is just XHTML Mobile Profile (a somewhat limited subset of HTML); everything else about it is the same as the normal web stack. This makes it much easier to work with: it's possible to generate content for desktop and phones from the same templates. You may also see ‘i-XHTML’, which is a similar HTML-subset used by Docomo phones.

Either way, modern smartphones are happy rendering normal desktop-style [X]HTML, so you're not going to have to worry about any of this in the future. (Sure, there are compatibility issues, but that's nothing new, right?)

Arrowhead

Is WAP 2 compatible with WAP 1,say, does it support <wml>/<card> any more? – Myrna

No. It's pretty much completely unrelated (hence the “misleadingly-named”). – Arrowhead

Answer 3

Here is a table with some information about the differences : http://csc.colstate.edu/summers/Research/Wireless/WAPvsWeb.html

Another difference being WAP is almost if not totally dead, and HTML is kicking ##S :-)

Yonyona

That link doesn't give any detailed difference. – Myrna