Best XHTML Validator for Linux (Xubuntu)

[Root23]

I'm currently taking a XHTML class at school, and the teacher requires that we validate all our HTML and provide a log file wit the homework we turn in.

For the class we use CSE HTML Validator, which he says is very good at finding things that even the W3C's validator doesn't find. Alas, there's no linux version of it.

What do you guys use? Recommendations?

[WingedPanther]

Usually, I stick with W3C or a Firefox plugin.

[Root23]

I've heard of the Firefox add-on before, maybe I'll check it out.

Thanks