Accessing serial port from browser window

[ashish.sadanandan]

Hi,
I'm not sure whether this is the right newsgroup to post this question
in, if it isn't please accept my apologies (and I'd really appreciate
it if you could point me to the correct one).
I'm not very familiar with XML, XSLT etc. so this may sound totally
outrageous but here's what I have in mind:

The problem is creating a dynamic user interface that talks to some
hardware that my company makes. We want to get away from C++ because
having to compile it for every build is putting severe restrictions on
our setup. So a new idea is to create XML sheets (using a scripting
language that runs along with every build). All elements of the user
interface would be described in this and then, using XSLT, transformed
into XHTML so that a web browser can display it.
Now, is the following part possible at all? Communication with the
hardware is using the serial port, so there needs to be some
underlying code handling this and interfacing with the web page. It
needs to send data to the web page and from the page back to the
hardware. Is there any language (that also plays nice with browsers)
that will allow this?
Also, another requirement is for the end user to be able to create
pages laid out in any arbitrary manner, for instance have variables
which are important to them be at the top (and maybe refreshing
faster) and others in another section of the page. Can XHTML handle
this? Or would we require Ajax?

Again, I apologize if I've butchered the terminology and used names
which are completely incorrect. I'm a C programmer and very much a
novice when it comes to web pages and their associated scripting
languages.

Thanks for your help,
Ashish.