Now called CiteSeerx (originally called CiteSeer) is a free public search engine and digital library for scientific and academic papers. It is considered as a predecessor of free academic search tools like Google Scholar, which primarily "harvest" documents from publicly available websites as opposed to scholarly publisher websites. For this reason, authors whose documents are freely available are more likely to be represented in CiteSeerx .
CiteSeerx is considered a valuable academic resource by most researchers and librarians. Its main strengths are in the fields of computer and information science, but it has some papers relevant to transportation.
According to "An Introduction to Search Engines and Web Navigation" by Mark Levene, CiteSeerx contained around 1.5 million full-text scholarly papers in 2010. The exact size today is not known.
According to the About CiteSeer page: "CiteSeer was the first digital library and search engine to provide automated citation indexing and citation linking by autonomous citation indexing" and "was developed in 1997 at the NEC Research Institute, Princeton, New Jersey, by Steve Lawrence, Lee Giles and Kurt Bollacker. The service transitioned to the Pennsylvania State University's College of Information Sciences and Technology in 2003."
The page goes on to note: "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.
