Alberto Accomazzi et al. have self-archived "ADS: The Next Generation Search Platform."
Here's an excerpt:
Starting in 2011, the ADS started to systematically collect, parse and index full-text documents for all the major publications in Physics and Astronomy as well as many smaller Astronomy journals and arXiv e-prints, for a total of over 3.5 million papers. Our citation coverage has doubled since 2010 and now consists of over 70 million citations. We are normalizing the affiliation information in our records and, in collaboration with the CfA library and NASA, we have started collecting and linking funding sources with papers in our system. . . . We have rolled out and are now enhancing a new high-performance search engine capable of performing full-text as well as metadata searches using an intuitive query language which supports fielded, unfielded and functional searches. We are currently able to index acknowledgments, affiliations, citations, funding sources, and to the extent that these metadata are available to us they are now searchable under our new platform. The ADS private library system is being enhanced to support reading groups, collaborative editing of lists of papers, tagging, and a variety of privacy settings when managing one's paper collection.