Luke – Lucene Index Toolbox
If you want to understand what’s in your Zend_Search_Lucene index files, then download Luke (http://www.getopt.org/luke/) and point it at the directory containing your index files.
This is screenshot of my test index:
Wow!
What a very useful tool!
The tool can also be used to build the index – see http://galide.jazar.co.uk/2010/09/luke-08-for-zend-lucene.html