Recoll is a personal full text search tool for Unix/Linux.
It is based on the very strong Xapian backend, for which it 
provides an easy to use, feature-rich, easy administration, 
QT graphical interface. Recoll is able to include several separate 
folders ("Top directories") in its search.

This requires xapian-core, with optional dependencies of antiword, unrtf,
and exiftool (all available at SlackBuilds.org).