This public Jenkins:
https://hudson.jboss.org/hudson/job/optaplanner/
Mirrors this internal Jenkins:
https://jenkins.mw.lab.eng.bos.redhat.com/hudson/view/Drools%20jBPM/view/Master/job/optaplanner/

The public Jenkins has a 2 day old build of 11-APR-2015, but the Last Successful Artifacts, optaplanner-distribution-6.2.0-SNAPSHOT.zip has not changed almost a year. And since a month or two, it should be optaplanner-distribution-6.3.0-SNAPSHOT.zip instead.

First reported here: http://stackoverflow.com/questions/29592529/where-could-i-download-the-optaplanner-6-3-nightly-snapshot