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.
Yadoda is a personal digital library: user can create his own ontology and a db of digital documents (pdf,ps,mp3,images) that can be enriched with metadata (author,date,title). User can create semantic relations between documents and navigate them.