John Cowan has released the final 1.0 version of TagSoup. What is TagSoup? It's a parser for cleaning up non-well formed HTML (I've had the pain of previously cleaning other people's messy code/content with some help from HTMLTidy, but mostly by hand. This mess is often called Tag Soup, or worse...).
John's parser cleans up the mess and creates well-formed XHTML. It's an immense time saver. More details and the download are available here: http://mercury.ccil.org/~cowan/XML/tagsoup/.