The ThermoData Engine fully implements all major principles of the concept of dynamic data evaluation formulated at NIST's Thermodynamics Research Center (TRC). Dynamic data evaluation relies on large electronic databases to store the currently known experimental data along with detailed descriptions of relevant metadata and uncertainties. Combining this data with expert software allows the ThermoData Engine to producing data compilations 'to order' which include all major thermophysical properties (such as density, vapor pressure, heat capacity, enthalpies of phase transitions, critical properties, melting and boiling points, etc). As the name of this resource implies, its scope is only pure compounds. For binary mixtures please see NIST ThermoData Engine - Pure Compounds and Binary Mixtures - SRD 103b (https://www.nist.gov/srd/nist-standard-reference-database-103b).