[Tracker] gnome-search-tool enhancement

[Deepak Mishra <dpux4linux gmail com>]

Hello list !!
I am new to this list, and very new to desktop search too. Please pardon me any behavior not suited to the list. To be honest, I have been redirected to this list by the gnome-love mailing list members regarding my query.
I am still reading a lot to know the exact search process. My doubts (and they are a lot !) are hence very basic.
As a user I (and my friends) have hardly ever found my search results impressive in GNOME (by the gnome-search-tool), and I aim at enhancing that tool. Even after a lot of googling I am yet to find out what indexing process does gnome-search-tool use as a backend.So can anyone please tell me the search engine used by the tool ?
I have also been through the beagle architecture and got to know that it uses the LUCENE search engine at core. But I could not get to know what search engine does tracker use, hope you people can tell me.
In the gnome-love list people said that gnome-search-tool "probably" uses libbeagle and libtracker. Is it true ? If it is, then why both ?? Any one could do !
Earlier I always had a thought that gnome-search used the "find" or "locate" utility in linux,but after going through it's source, I discovered I was wrong. But I feel even the "find" utility must be making an index for its use....cant we simply use it ? 

Hope you people will help me out !
Thanks in anticipation.
Deepak Mishra