Zilverline is what you could call a 'Reverse Search Engine': Zilverline is a search engine that offers web access to your personal or intranet content.Zilverline supports collections: a set of files and directories in a directory. Zilverline extracts content from PDF, Word, Excel, Powerpoint, RTF, txt, java, CHM as well as zip, rar, and many other archives. Reference:https://www.zilverline.org/zilverlineweb/space/home