Qtopia and Qt embedded

Hi,

I am new to Qt embedded. For that matter, I am new to embedded programming.
I am working for a project (few years old) and it uses Qtopia.

When I googled for Qtopia, I found the following info.

http://doc.trolltech.com/qtopia1.7/index.html

So, my questions are,
1. Is it not maintained by Nokia? If it is part of Qt, why don't I see "Qtopia" term in nokia website?
2. Do I have to have license for Qtopia?
3. Is it not available in Qt SDK as a part of it?

As I understand, Qt is a cross-platform application and UI framework using which we can write applications once and deploy them across desktop, mobile and embedded operating systems without rewriting the source code.
Which means, I can install Qt SDK, develop application on windows (which I prefer) and deploy on embedded Linux. In that why would anyone purchase Qtopia developer licenses?

Or is it that Qtopia has special APIs for embedded?

I have been working on Qt all this time on windows platform so know nothing about embedded/embedded linux. Please pardon my ignorance...

Thanks...