This is OLD site. The new site is http://fess.codelibs.org/.
Fess is Java based full text search server provided as OSS product. You can install and run Fess quickly on any platforms, which have Java runtime environment. Fess is provided under Apache license.
Fess is built on Seasar2 framework, and contains Apache Solr. A crawler used by Fess is S2Robot, which can crawl documents on Web/Local File System and support many file formats, such as MS Office, pdf and zip.