Confio Software - Ignite for SQL Server
Ignite for SQL Server is designed specifically to solve and prevent the toughest performance problems. It's not a general purpose monitor - server health tools do that. Ignite goes where conventional tools cannot. With easy to understand graphical displays, and automatically emailed graphic reports, Ignite is the one tool that DBAs, developers, and managers can use to collaborate.
No Agents. No Tracing. Less than 1% load on monitored servers makes Ignite the lightest high performance monitoring tool available.