www.treasure-troves.com
An
excellent quick reference for lots of
science stuff which was created and is constantly updated by
Eric W. Weisstein.
There is information on:
For those interested in such things, the raw information is in TeX, which is then converted to HTML for them web using LaTeX2HTML. Also, (at least the math section) has lots of internal links to other topics, much like Everything, which allows node surfing.