When it comes to mobile development on .NET platform I've only developed for Win CE and Win Mobile, but a provider offered me Win XP Embedded on some industrial computer we're going to use.
The question is, how do you programm for this OS, is this just a minimized version of Desktop's Win XP?, should I use the same kind of projects and framework targeting on Visual Studio?
On
You program like you do for a regular Windows version. But it is up to the system builder to decide what parts of Windows will make it onto the machine. If it is a headless version of Windows (no video support) then of course writing a GUI program is a waste of time. You'll need to talk to the system builder and tell him what you need. Or ask what's available, it isn't usually clear who makes the choices. Running the builder yourself is a good way to get a feel for what the options are.
Windows CE and XP Embedded are just two tiers of the same product. They both have very similar tool-chains. They both use the same compartmentalized technology, if you are similar with Win CE, it wont be too big of a change going to XP Embedded.
The Windows Embedded website. Windows CE is the "Compact" line, and XP Embedded is the "Standard" line.
To answer your question in your post. XP Embedded is more like a feature rich Win CE than a striped down XP.