A Java implementation of a desktop search engine based on Apache Lucene. It indexes HTML-, XML-, OpenOffice- (Writer, Calc, Impress), MS Word-, and PDF- documents as well as plain text files. For other, arbitrary file types the file name can be indexed.
DuMP3 is a duplicate and similar file finder. It finds exact duplicate binaries by hash, similar text files by substring content, images (JPG, BMP, GIF, PNG, etc) by color and audio files (MP3, WAV, OGG, etc) by wave data. Future: fonts, video.
InfoSpace is an application which indexes and then allows you to search your personal information space, such as your email, your documents, your music, your videos, your Flickr account, your news feeds, the web pages you've visited and much more.