Citeseer
CiteSeer was a public search engine and digital library for scientific and academic papers, primarily in the fields of computer and information science, that has been replaced by CiteSeerX. Many consider it to be the first academic paper search engine. It became public in 1998 and had many new features unavailable in academic search engines at that time. These included:
It is often considered to be the first automated citation indexing system, has a patent on this topic, and was considered a predecessor of academic search tools such as Google Scholar and Microsoft Academic Search. CiteSeer-like engines and archives usually only harvest documents from publicly available websites and do not crawl publisher websites. As such authors whose documents are freely available are more likely to be represented in the index.
CiteSeer's goal is to improve the dissemination and access of academic and scientific literature. As a non-profit service that can be freely used by anyone, it has been considered as part of the open access movement that is attempting to change academic and scientific publishing to allow greater access to scientific literature. CiteSeer freely provided Open Archives Initiative metadata of all indexed documents and links indexed documents when possible to other sources of metadata such as DBLP and the ACM Portal. To promote open data, CiteSeerX shares its data for non-commercial purposes under a Creative Commons license.
The name can be construed to have at least two explanations. As a pun, a 'sightseer' is a tourist who looks at the sights, so a 'cite seer' would be a researcher who looks at cited papers. Another is a 'seer' is a prophet and a 'cite seer' is a prophet of citations. CiteSeer changed its name to ResearchIndex at one point and then changed it back.
CiteSeer was created by researchers Lee Giles, Kurt Bollacker and Steve Lawrence in 1997 while they were at the NEC Research Institute (now NEC Labs), Princeton, New Jersey, USA. CiteSeer's goal was to actively crawl and harvest academic and scientific documents on the web and use autonomous citation indexing to permit querying by citation or by document, ranking them by citation impact. At one point, it was called ResearchIndex.
...
Wikipedia