raniko wrote: okay. What does the RC mean? Is that a development version?

RC = Release Candidate

The process of release is as follows:

-> alpha builds (usually internal team testing)
-> beta builds (available to Developer members)
-> RC builds (available to Professional members)
-> stable releases

So GroupJive 2.5 went through the following process:

-> GroupJive 2.5 RC1
-> GroupJive 2.5 RC2
-> GroupJive 2.5

So latest - newest package is GroupJive 2.5 and that is what you should install.