Anyone who has used Reaction101 or Yield101 will know that these apps have access to a collection of common reactions that can be used as a helpful reference, or as a starting point for drawing new reaction schemes. The reaction data has received a bit of an overhaul and cleanup, and is now also viewable online. Follow the link to see the reactions organised into categories, which can be browsed, rendered and downloaded in a variety of different cheminformatics and graphics formats.