This page documents the process you will need to go through to setup the Sphinx search system that Dreamwidth uses. This is not an easy process, and the documentation is probably going to need some iterations to get to a very useful state.
I only suggest setting up the search system if you have a good amount of time to mess around with things. If you need some help, feel free to grab me anytime and I'll help out.
First, you will need to setup the Sphinx software. Very first, you should make sure you have some packages (Ubuntu Intrepid):
apt-get install libpath-class-perl libmysqlclient15-dev g++
There are three packages that you will have to download:
http://sphinxsearch.com/downloads/sphinx-0.9.8.1.tar.gz http://search.cpan.org/CPAN/authors/id/J/JJ/JJSCHUTZ/Sphinx-Search-0.12.tar.gz http://search.cpan.org/CPAN/authors/id/T/TJ/TJENNESS/File-SearchPath-0.05.tar.gz
Now, you need to build these. The second two are standard Perl packages which you can build with dh-make-perl. Do File::SearchPath first (and then install it) and then you can build Sphinx::Search (and install it).
The Sphinx package itself is a standard project style. Setup and installation looks something like this:
tar -zxvf sphinx-0.9.8.1.tar.gz cd sphinx-0.9.8.1/ ./configure make make install
Assuming that all works, you should have everything installed that you need to get the search system setup. Moving on!