Chemicalize from ChemAxon
This is a great way to mark up compounds in web pages and then move over to the data pages for predicted properties. The predicted property capabilities is a great offering to the community. The predictions are licensed under Creative Commons “Attribution-NonCommercial-ShareAlike 3.0 Unported”. The site has a few teeting troubles, especially in terms of layout on IE8, but this should not detract from the value of the predictions. I am not aware of any other site that will provide free access to pKa predictions as shown below. This will really commoditize the market at this point and shake up the other vendors in this domain. ChemSpider has recently integrated Chemicalize as discussed on the ChemSpider blog.Read the post on The ChemConnector Blog!