NASA Astrophysics Data SystemThe Astrophysics Data System (ADS) is a NASA-funded project whose main resource is an Abstract Service, which includes four sets of abstracts: 1) astronomy and astrophysics, containing 542,317 abstracts; 2) instrumentation, containing 576,466 abstracts; 3) physics and geophysics, containing 877,721 abstracts; and 4) Los Alamos preprint server, containing 3,561 abstracts. Each dataset can be searched by author, object name (astronomy only), title, or abstract text words. In addition, we have extended the abstract service to include links to the full text of articles appearing in most of the major astronomical journals.