OpenKM is a powerful and scalable multiplatform application for document management, based on open technology (Java, Tomcat, GWT, Lucene, Hibernate, Spring and jBPM). OpenKM is a Web 2.0 application that works with Internet Explorer, Firefox, Safari and Opera.
OpenKM supports WebDAV and webservices interfaces and can be configured in major DMBS like Oracle, PostgreSQL and MySQL among others.
Due to its technological architecture design, OpenKM meets the document management needs of businesses of all sizes (from SMEs to big corporations). Thanks to its elegant and intuitive interface, OpenKM transforms complex operations into easy tasks.
The most relevant functions of OpenKM is the indexing of the most common types of files: text, Office, Office 2007, OpenOffice, PDF, HTML, XML, MP3, JPEG, etc.
For a complete feature list take a look at http://www.openkm.com/en/overview/comparison-of-versions.html