Lemur Project

The Lemur Project develops search engines, browser toolbars, text analysis tools, and data resources that support research and development of information retrieval and text mining software. The project is best known for its Indri search engine, Lemur Toolbar, and ClueWeb09 dataset. Our software and datasets are used widely in scientific and research applications, as well as in some commercial applications.

Indri is a search engine that provides state-of-the-art text search and a rich structured query language for text collections of up to 50 million documents (single machine) or 500 million documents (distributed search). Available for Linux, Solaris, Windows and Mac OSX.

Features Powerful Query Interface

Supports popular structured query operators from INQUERY Suffix-based wildcard term matching Field retrieval Passage retrieval

Flexible Indexing and Document Support

Supports UTF-8 encoded text Language independent tokenization of UTF-8 encoded documents. Parses PDF, HTML, XML, and TREC documents Word and PowerPoint parsing (Windows only) Text Annotations Document Metadata

Package Versatility

Open source, with a flexible BSD-inspired license Includes both command line tools and a Java user interface API can be used from Java, PHP, or C++ Works on Windows, Linux, Solaris and Mac OS X

Scalability and Efficiency

Best-in-class ad hoc retrieval performance Can be used on a cluster of machines for faster indexing and retrieval Scales to terabyte-sized collections

Download Indri can be obtained from the SourceForge Lemur Project Page. Release History The first version (1.0) of Indri was released in Jan 2002. Subsequent releases have been made 2-3 times each year since then. Release notes for the current release can be found on SourceForge.