Xapian

Xapian is an open source probabilistic information retrieval library, released under the GNU General Public License (GPL). It is a full text search engine library for programmers.

It is written in C++, with bindings to allow use from Perl, Python, PHP, Java, Tcl, C#, Ruby, and Lua. Xapian is highly portable and runs on Linux, Mac OS X, FreeBSD, NetBSD, OpenBSD, Solaris, HP-UX, Tru64, IRIX, Microsoft Windows,^[1] GNU Hurd,^[2] and OS/2.^[3]

Xapian is designed to be a highly adaptable toolkit to allow developers to easily add advanced indexing and search facilities to their own applications.

A growing number of organisations and projects are known to be using Xapian including Debian, Gmane, Die Zeit, Delicious, MoinMoin, and One Laptop per Child.^[4]

Features

• Transactions: if database update fails in the middle of a transaction, the database is guaranteed to remain in a consistent state.
• Simultaneous search and update, with new documents being immediately visible.
• Support for large databases: Xapian has been proven to scale to hundreds of millions of documents.
• Accurate probabilistic ranking: more relevant documents are listed first.
• Phrase and proximity searching.
• Relevance feedback, which improves ranking and can expand a query, find related documents, categorise documents etc.
• Structured Boolean queries, e.g. "race AND condition NOT horse"
• Wildcard search, e.g. "wiki*"
• Spelling correction
• Synonyms
• Omega, a packaged solution for adding a search engine to a web site or intranet. Omega can easily be extended and adapted to fit changing requirements.

See also

• List of information retrieval libraries
• Recoll

References

External links

• http://xapian.org is the Xapian project website.
• Flax is an open-source enterprise search engine based on Xapian.
• Recoll is a desktop search tool based on Xapian.
• DualWord-index - Xapian index viewer.