Hi, You can download the release candidate from http://people.apache.org/~shinichiro/apache-manifoldcf-0.5.1-RC1/ and there is also a tag in svn under https://svn.apache.org/repos/asf/incubator/lcf/tags
RC1 includes revising the pom.xml versions. I've already checked signatures. Thank you, Shinichiro Abe