Nepomuk/Strigi is a very powerful desktop search in KDE. Strigi is the file indexer which allows for search not just by the file name but by the content of the file as well and Nepomuk is allows for the tagging and rating of the files and it is integrated along with the desktop search.

In Kubuntu 9.10/KDE 4.3, Nepomuk/Strigi is disabled by default. To enable it follow these steps:

1. Press "Alt+F2" to launch KRunner.
2. Enter Strigi in KRunner and run Desktop Search.
3. In the Desktop Search Control Module, under the Basic Settings tab, check both the check boxes next to Enable Nepomuk Semantic Desktop and Enable Strigi Desktop File Indexer.
4. Click on Apply.

It is very possible that you get an error which says "Service failed to initialize, most likely due to an installation problem" with Strigi when you click on Apply. This is due to a problem with the Java Runtime and can be fixed by a simple symbolic link. Here is the fix for it:

Find out if you are using OpenJDK or Sun Java

If you do not know if you are using OpenJDK or Sun Java, open Konsole and run the command

java -version

Now you will get to know if you are running OpenJDK Runtime Environment or Sun Java Runtime Environment. As you can see from the screenshot below, I am running OpenJDK.

Open JDK Runtime Environment

If you have OpenJDK Runtime Environment, run the command given below

For 32-bit:

sudo ln -s /usr/lib/jvm/java-6-openjdk/jre/lib/i386/server/libjvm.so /usr/lib/libjvm.so

For 64-bit:

sudo ln -s /usr/lib/jvm/java-6-openjdk/jre/lib/amd64/server/libjvm.so /usr/lib/libjvm.so

Sun Java Runtime Environment

If you have Sun Java Runtime Environment, run the command given below:

For 32-bit:

sudo ln -s /usr/lib/jvm/java-6-sun/jre/lib/i386/server/libjvm.so /usr/lib/libjvm.so

For 64-bit:

sudo ln -s /usr/lib/jvm/java-6-sun/jre/lib/amd64/server/libjvm.so /usr/lib/libjvm.so

After running running the command for either OpenJDK or Sun Java Runtime, click on Apply again and Strigi should be working now.