opsview

I just heard about this yet anothe tool that works with nagios its called opsview.

Opsview is the award winning Open Source application and infrastructure
monitoring software from Opsera. It provides comprehensive system
management capabilities used to monitor the health of today’s most
complex data centres.
Opsview provides a central, web-based console from which you can
monitor, diagnose and manage all your enterprise IT resources.
Opsview significantly extends the capabilities of Nagios and Nagios
plug-ins and many other open source components into one single,
coherent system
Taking Nagios to the next level
Opsview
Opsview is the award winning Open Source application and infrastructure
monitoring software from Opsera. It provides comprehensive system
management capabilities used to monitor the health of today’s most
complex data centres.
Opsview provides a central, web-based console from which you can
monitor, diagnose and manage all your enterprise IT resources.
Opsview significantly extends the capabilities of Nagios and Nagios
plug-ins and many other open source components into one single,
coherent system.
Opsview and Nagios
Nagios® is used by thousands of organisations worldwide for network,
server and application monitoring. Organisations chose Nagios because it
is open, mature, and well supported. A thriving community exists and
Nagios is under constant development by project lead Ethan Galstad.
Nagios is focussed on doing one job very well. As a result, a number of
Open Source projects have sprung up around Nagios to extend its
capabilities, the most significant of these being the Nagios Plugins project.
Opsview has been developed to fully integrate these components and
provide an intuitive user interface for managing the system.
Altinity’s philosophy is to use existing Open Source software where
possible and improve as required. On this basis, Opsview integrates
existing software components into a single coherent system. The main
body of new code developed by Altinity has gone into the middleware
integration layer, and the web user interface.
Benefits of Opsview for existing Nagios systems
Opsivew represents a simple upgrade path for existing Nagios systems.
System Management
Although Nagios is capable of monitoring thousands of devices,
maintaining system configuration can become problematic on large
deployments. Opsview addresses this issue by providing an intuitive web
user interface and a middleware layer that handles the complexity of
configuring each individual software component.

Personally I have not tried the product but the Web GUI is much poor then Centreon.
Take a look on the online demo
More info on their site:
http://www.opsera.com