Regain is a Java search engine based on Jakarta Lucene. It provides indexing and searching files for plenty of formats (HTML,XML,doc(x),xls(x),ppt(x),oo,PDF,RTF,mp3,mp4,Java). A TagLibrary eases integrating search results in your JSP based web page.
Mustru is a desktop Q&A search engine based on Lucene. You can search local filesystems using natural language questions or boolean queries. A list of answers or hits will be returned. A web based interface is included.