* BRENDA - a comprehensive enzyme information system - Available from Technische Universität Braunschweig
* ChemInfo - Chemical Information Sources - an open-content textbook collection.
* ChemSeer -- This is another source of information on chemistry societies, but if you link to Journals, Careers, and any of the additional selections across the top of the page you can explore even further this chemical resource!
* Google Book Search - allows users to search the content of books and, "if the book is out of copyright, or the publisher has given (Google) permission, you'll be able to see a preview of the book, and in some cases the entire text. If it's in the public domain, you're free to download a PDF copy.
* IPL ( Internet Public Library ) - this link will take you to the Chemical Sciences collection on the IPL. Links are to books, newsletters, tutorials, and more.
* Kaye and Laby Online - This is a free version of "The Kaye and Laby Table of Physical and Chemical Constants" (16th ed., 1995). Contains lots of tables, formulas, graphs, and more. A useful handy tool for the serious researcher. The data is regularly reviewed and updated.
* Openmolecules.org - this website was published as a platform to publish cheminformatics tools for synthetic and medicinal chemists. N.B. Some of these programs / databases require you to download applets to launch them, and so some are strictly MAC tools.
* WebElements - An interactive periodic table of the elements from Mark J. Winter, Department of Chemistry, University of Sheffield, England.
* Wired Chemist - this site contains instructional animations, modules, demonstrations and more in the fields of Chemistry and Biology.