Xapian-omega is a project mainly written in SHELL and C++, based on the GPL-2.0 license.
This directory contains two index building utilities (omindex and scriptindex) and a CGI search application (omega). These use the Xapian search library to provide a search over a collection of documents.
See INSTALL for installation instructions.
Once you've built and installed Omega, you can find documentation explaining how to use it in the docs subdirectory of the omega source code. A good place to start is to read docs/quickstart.html followed by docs/overview.html.
If you are trying to build from SVN, see the HACKING document in the xapian-core tarball for details.