Linking to HTML Validation service from client application

This probably isn't necessary given previous threads such as
http://lists.w3.org/Archives/Public/www-validator/2001JulSep/0484.html ,
but just to be sure, I'm wondering if any permission is necessary to
call the W3C's HTML validation service from within a desktop
application?

Our plan is to link line numbers shown in the validator output with line
numbers in our editor, so users can quickly correct mistakes.  Can we go
ahead and do this, or should we be talking to someone at the W3C to get
permission first?

Thanks,
---
Nick Bradbury
TopStyle CSS/HTML/XHTML Editor
http://www.bradsoft.com/