Related data about elliptic curves, abelian varieties, etc.
William A. Stein
Collection of Tables Related to Modular Forms, Elliptic Curves, and Abelian Varieties
The Modular Forms Explorer (PostgreSQL)
The Interactive Modular Forms Explorer (uses ZOPE)
The Stein-Watkins tables of elliptic curves (see also the paper).
Elliptic Curves Information Calculator
PARI & MAGMA Calculator
Bibtex Reference for the Database
Talks About the Database
Lecture Notes
Software