If you ever wanted to search through the whole Lucene ecosystem (Lucene Java, Mahout, Tika and more) your possible solution of choice is the search engine by Lucid Imagination. It searches through project websites, wikis, mailing-lists (public, dev) and the source code itself – its indexiation performance is also pretty impressive.
Lucid Imagination is a company founded by Marc Krellenstein, Yonik Seeley, Grant Ingersoll and Erik Hatcher (a team of experts) which provides professional search (and beyond) solutions for the enterprise based upon Lucene.
Update: comment about Lucid Imagination from Beyond Search
