CiteSeerX

**History and Development of CiteSeerX**:
– CiteSeer was created in 1997 by Lee Giles, Kurt Bollacker, and Steve Lawrence at the NEC Research Institute.
– In 1998, CiteSeer became public with features like autonomous citation indexing and reference linking.
– CiteSeer obtained a US patent for autonomous citation indexing in 2001.
– CiteSeer.IST was hosted at The Pennsylvania State University from 2004, housing over 700,000 documents.
– CiteSeerX succeeded CiteSeer, launched in 2008 as a public search engine and digital library expanding beyond computer science.
– CiteSeerX is funded by organizations like the National Science Foundation, NASA, and Microsoft Research.
– Currently, CiteSeerX hosts over 6 million documents with 6 million unique authors and 120 million citations.

**Features and Usage of CiteSeerX**:
– CiteSeerX uses automated tools like ParsCit for metadata extraction from scholarly documents.
– Focused crawling is done on publicly available scholarly documents, mainly from author webpages.
– CiteSeerX has nearly a million users globally with millions of daily hits and 200 million annual document PDF downloads in 2015.
– Data from CiteSeerX is shared under a Creative Commons license and widely used in research experiments.
– The platform caches PDF files and provides a DMCA link for reporting copyright violations.
– In 2015, CiteSeerX had nearly 200 million annual downloads of document PDFs and is considered a valuable resource for academic literature access.

**Impact and Significance of CiteSeerX**:
– CiteSeer is part of the open access movement, promoting greater access to scientific literature.
– It serves as a predecessor to academic search tools like Google Scholar and Microsoft Academic Search.
– CiteSeer aims to improve the dissemination and access of academic and scientific literature.
– The platform freely shares its data for non-commercial purposes under a Creative Commons license.
– CiteSeer’s modular open-source architecture allows testing new algorithms in document harvesting and indexing.

**Other SeerSuite-based Search Engines**:
– CiteSeer model extended to cover academic documents in business with SmealSearch and in e-business with eBizSearch.
– Older versions of SmealSearch and eBizSearch were once found at BizSeer.IST.
– Other Seer-like systems built for chemistry (ChemSeer) and archaeology (ArchSeer), and a system for robots.txt file search called BotSeer.
– All systems built on SeerSuite, using the Lucene indexer.

**Related Resources and References**:
– Related resources include Arnetminer, arXiv, Collection of Computer Science Bibliographies, and DBLP.
– References include CiteSeerX Data Policy, Conceptual recommender system for CiteSeerX, ResearchIndex, and About CiteSeerX.
– Further reading on CiteSeer: an automatic citation indexing system.
– External links to the official CiteSeerX website and categories like Bibliographic databases in computer science.