The API for the Incorporated Research Institutions for Seismology’s (IRIS) Seismographs in Schools Program returns XML. It retrieves stations, station information, events, event information, and networks affiliated with IRIS.
Our API directory now includes 195 science APIs. The newest is the AnnotQTL API. The most popular, in terms of mashups, is the NCBI Entrez API. We list 4 NCBI Entrez mashups. Below you'll find some more stats from the directory, including the entire list of science APIs.