gives seamless immediate access to an ever-growing library of carefully curated and continually updated data maintained by Wolfram Research—all with a unified interface allowing complete interoperability and tight integration into Mathematica
and its computational and data presentation capabilities.
bulk, atomic, chemical, etc. properties of chemical elements
structural, physical and other properties of chemical compounds
static and decay properties of all nuclear isotopes
properties of stable, unstable and resonance particles
properties of stars, planets and other objects
many categories of data about countries, groups, etc.
properties of 250,000+ cities around the world
current and historical stock, fund, index, currency, etc. data
use string patterns to look up words in the dictionary
properties of words and network of relations between them
many types of standard test and example data
symbolic representation of missing data