60% of my fav links from 10 yrs ago are 404. I wonder if Library of Congress expects 60% of their collection to go up in smoke every decade.– Bret Victor (@worrydream) on Twitter, 2014-06-15I'm keeping this page alive for the few people who have bookmarked it. The only things that get regular traffic are my chemistry lab protocols from 2011. I hope students are using them for serious study and not for cheating.