If a div is given a background colour and contains floated items (floated using CSS’s float or HTML ’s align on images), things can go very wrong in Internet Explorer – screenshot of my examples page in IE6 , compared with how it should look .
HTML Tidy is a tool that was originally written by Dave Raggett of the World Wide Web Consortium (W3C) . It is designed to fix mistakes in HTML, tidy up the layout (hence the name), assist with web accessibility, convert HTML to XHTML and many other things.