Thanks! For everyone's information, we are running Scientific Linux 6.3 which is a re-branded release of Red Hat Enterprise Linux 6.3 with some added tweaks and packages. We have had no issues running the Retrospect 7.7 Client on this version. Based on this, the client should also work on the RHEL-6.3 and CentOS-6.3 version but we have not tested it.
We are currently using Retrospect Professional for Windows 7.7 to backup both Windows and Linux clients. The question is; does the new version, Retrospect Professional for Windows 8 support Linux clients? If not, is there plans in the future to support Linux clients?