Winspector Spy - Have you ever used Spy++ that comes with MSVC?
ServerSuit - ServerSuit is a browser based program that enables remote Linux administration, monitoring, website hosting, and server setup automation.
WinSpy - Retrieve window information.
RedGate SQL Monitor - SQL Monitor helps you and your team find issues – before they become problems
Microsoft Spy++ - Spy++ (SPYXX.EXE) is a Win32-based utility that gives you a graphical view of the system’s...
Nagios - Complete monitoring and alerting for servers, switches, applications, and services