Nagios Support Forum

As I read the overviews and look over the screenshots all seem to monitor devices. I can see that XI is a professionally managed configuration, but it gets confusing after that which product you'd want to use.

It looks like V-Shell is separate from Core, which makes me wonder what it's purpose is? Is Fusion also a separate program and if so what does it really do different from Nagios Core of V-Shell?

V-shell is an overlay for core, it allows you to view the web interface in a different fashion, think theme. Fusion, as it's product page shows, allows you to tie all of your Core/Xi servers together in one view, see their host/service status details, alerts, and then filter down and drill into the specific servers from the Fusion web interface. It's more of a centralized dashboard if you will. You can demo them all by visiting http://demos.nagios.com