http://validator.w3.org/source/
Instructions for that one are only a couple clicks away:
<http://www.mediaville.net/articles/validator/>
Thank you. I had no idea. Checking it out now.
It's possible to install these tools on LINUX using PPM
I think you're confused - Linux is not an ancronym, and PPM is for Windows. :-)
Yes, indeed, sorry. Hangover. Please substitute "Linux" and "RPM".