Hyper Estraier is a full-text search system.  You can search lots of
documents for some documents including specified words.  If you run a
web site, it is useful as your own search engine for pages in your
site.  Also, it is useful as search utilities of mail boxes and file
servers.

The characteristic of Hyper Estraier is the following.

    * High performance of search
    * High scalability of target documents
    * Perfect recall ratio by N-gram method
    * Phrase search, attribute search, and similarity search
    * Multilingualism with Unicode
    * Independent of file format and repository
    * Simple and powerful API
    * Supporting P2P architecture

Hyper Estraier is an open-source software released under the terms of
the GNU Lesser General Public License.  It works on Linux, Windows,
Mac OS X, and other UNIX-like systems.