I want to take a link (and grab its HTML) and only keep the part that is important, say the article. There are many HTML parsing libraries for Objective-C - hpple, for example - but I want to do more than just parse specific things, I need something that removes all the things that aren't part of the readable content. Kinda like what Instapaper, Readability, Pocket or Safari's Reader feature do.
What would be the best way to accomplish this in Objective-C/iOS?