I don't know about a parsing library, but the HTML5 spec defines how parsers for it should behave, so at least at some point in the not-too-distant future, it s

I don't know about a parsing library, but the HTML5 spec defines how parsers for it should behave, so at least at some point in the not-too-distant future, it shouldn't matter too much. I think Chrome/Safari already implement it (or at least are fairly close) and Firefox has its own implementation coming in Firefox 4. If you're looking for one to do HTML scraping, I think it really depends on the language you're using, and I don't think there's a single gold standard.