Document search in Lucene/Solr, Whoosh, Sphinx, Xapian

I am comparing Lucene/Solr, Whoosh, Sphinx and Xapian for searching documents in DOC, DOCX, HTML and PDF. Only Solr is documented to have a document parser (Tika) which directly in开发者_StackOverflow中文版dexes documents. So it seems a clear winner.

But to level the playing field, I like to consider the alternatives. Do the others have direct document indexing (which I may have missed)? If not are they can it be implemented easily? Or is Solr the overwhelming choice?

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On Sphinx you're able to convert file using a PHP script through the xmlpipe_command option. Since PHP has a Tika-wrapper, writing the script and the setup itself aren't hard.