[html5] Questions about Validator.nu

[Marc Gueury]

Hi all,

I am the author of a quite old Firefox extension (before Firefox v1...)  
called HTML Validator. (http://users.skynet.be/mgueury/mozilla/)
It is an free /  open source package that I wrote during my free time. 
It contains HTML Tidy and OpenSP to help people
to correct their HTML pages. The validation is done locally in the 
browser (or offline) and without a second request to the server.

1) OpenSP was mostly used to get the same errors than validator.w3.org
2) and Tidy to cleanup the pages

I would like to do the same for HTML 5.
So, I looked recently at the HTML 5.
But I do not find how.

I was interested Validator.nu. And I have some questions:

Q1.  Is it right that validator.nu is only a web program that I can not 
run at the command line to give the list of errors of page ?
        * Would it be possible to run this from the command line ?
        * If yes, what would the size of the program I would need ?
        * Where can I find information about this ?
        * Or will HTML 5 validation stay only an online validation ?
Q2. I understood from the author of Tidy that there is nothing like HTML 
Tidy in HTML 5 ?
        I mean something to produce a clean HTML file from a wrong file.
        Would it not be quite simple to build something similar based on 
all the code and the testcase available in validator.nu ?
        Ex: - take the Html Parser, then write some code to produce a 
output.
               - With command line parameters similar or identical to Tidy ?
Q3. Is this mailing list the best place to discuss about this ?

Thanks,

Marc