FYI:
I’ve added a small UI to the tool, so command-line-impaired users can validate an 2.0 document without opening a prompt.
The UI starts if you call lynx without parameters (e.g. double click on the lynx.jar file).
You can also try to start it directly from the Web, here:
http://okapi.opentag.com/webstart/lynx/lynx.jnlp
The program is signed, but depending on your browser and which version of java you have, you may get warnings. On the Mac you may have to re-associate the .jnlp extension with its app.
Cheers,
-yves