Since ProDT is developed under the Eclipse architecture, it is deployed as a set of plugins which you can install into your current Eclipse installation.
Although, to make things simpler, it is also deployed as an entire Eclipse with ProDT's plugins already installed (the SDK) for Linux and Windows.
1) Extract the contents of of ProDT's .zip/.tar.gz in a new directory.
2) Launch Eclipse using the executable named eclipse on the root of the extraction directory.
3) Configure the prolog compiler.
1) If you don't have an Eclipse already installed, you can use one of this according to your operative system Eclipse 3.6
2) If you used the update site instead of downloading the plugins manually go to step 6)
3) Extract the contents of the eclipse's zip/.tar.gz file.
4) Inside it you will find a directory called dropins which is where you should copy the the contents of ar.com.tadp.prolog_1.0.0.zip which contains the ProDT plugin and its dependencies.
5) Launch Eclipse using the executable named eclipse on the root of the extraction directory.
6) Configure the prolog compiler.