Agentless, real-time monitoring of networks and applications.
Identify hop-by-hop network performance.
Monitor end-to-end performance through service-provider MPLS clouds or on private networks.
Hosted service with minimal configuration required.
Room for Improvement:
Uses "micro-appliances" which must be installed onto the network.
Does not perform traditional SNMP/CLI/NetFlow/WMI etc monitoring.
AppNeta provides a range of products, all based around intelligent network testing algorithms. PathView cloud is their hosted service, relying on miniature plug and play network devices which phone home to the cloud service.
The "micro-appliances" are actually network sequencers which generate network traffic, then record and process the results. The general idea is to target an end-device (server, router, etc), with the intent of measuring the path between the micro-appliance and the end-device.
The application is designed to monitor network paths, not necessarily devices so won't replace your NMS. But, it does a surprisingly good job of detecting network capacity, as well as potential problems with a path.