Flare plugin (with Ruby Solr library and acts_as_solr plugin)

Hello,

I'm looking for informations about this plugin (Flare).
http://wiki.apache.org/solr/Flare/
Is it a final plugin? Can we use it on final production application?
Have you some documentation / tutorial about it? I don't find
anything !

I would be grateful to your help that you bring to me.
Vincent