We currently use Github to host the code of JaCoP. We also use SourceForge to host binaries (jars). You can download the newest release by following the link here.
There are two options. You can download an executable jar file and use it to execute any example or flatzinc file. It is also possible to download a zip file containing sources and unpack it into your Intelij IDE/Eclipse workspace and create a new Java Projects, one named JaCoP and the other named ExamplesJaCoP.
Core Developer Team