There are different ways to get Silence. Arch Linux users can find it in AUR. Thanks to the openSUSE Build Service there are packages for some distributions. You can find them there or at KDE-Aps.org.
But you can also download the sources and compile it yourself.
Download SourcesVersion 0.2.1 - Download
Version 0.2 - Download
GitoriousCheck out the current version from Gitorious.
git clone git://gitorious.org/silence/silence.git
You need KDE4 libs to compile Silence.Change into the projects directory and execute the following commands.
mkdir build cd build cmake .. make # as root: make install