Ian Bicking: the old part of his blog

Comment

Take a look at Jesse Ruderman's Blogidate XML Well-formedness bookmarklet: http://www.squarefree.com/archives/000033.html

When you activate the bookmarklet, it checks all of the textareas on the current page and changes their background colour to green or red depending on whether or not they contain valid XML.
Comment on HTML spellcheck
by Simon Willison