The program formerly known as 'Dantz Retrospect' was a mainstay of the Mac community in the 1980s and early 1990s. Sometime in the late 1990s, when the Mac was really dying, Retrospect ran out of steam. By the time the Mac flamed on again, Dantz had lost its mojo; the application never got the care and feeding it needed and the customer base never returned. (In fairness to Dantz, the 21st century Mac is a consumer product and Retrospect was a SOHO/corporate solution.)
Now the decaying remnant of Retropsect is owned by EMC Insignia. I still use Retrospect Pro, but I don't know anyone else who does. There are few Amazon reviews and no respectable reviews anywhere else. No decent blogger confesses to using it (ok, there's me, but I'm not decent). There are no free downloads and no user forums. It's fair to say that EMC is simply feeding off a decaying user base.
All of which is by way of introducing a curiousity. I recently terminated NAV and installed a trial version of Microsoft OneCare. That means I have a better firewall than I used to. Today I found that Retrospect Pro had hung during a LAN backup. The firewall told me that it had blocked Retrospect's acccess to the net. I allowed access to Retrospect and the backup resumed.
Retrospect uses an internet registry to find the address of machines it backs up. That's how it can do backups across a WAN. One day, of course, EMC will give up and turn off that service. I think there's a workaround (hard code the IP addresses probably), but it is interesting to see examples of remote application disabling that date back to the 1990s.