WinSpy++!

Process Hacker is a feature-packed tool for manipulating processes and services on your computer. A free and open source process viewer with powerful process termination and memory searching/editing capabilities.

System Explorer is an enhanced Taskmanager that provides detailed information about running processes, startup programs, IE add-ons (BHOs), drivers, services network connections, system resources and more. It also keeps track of a history of processes that were started, and allows you to create file and registry snapshots that can be compared to analyze system changes in detail. System Explorer integrates online lookups into the right click menu for any process, driver or service, allowing you to retrieve additional information (and virus checking) from online sources including Google. »

Glances is a CLI curses based monitoring tool for GNU/Linux and BSD OS. Glances uses the PsUtil library to get information from your system. It is developed in Python.

Window Detective is a programmer's tool used to "spy" on an application's windows and allows you to view and even modify some of its properties.

Spy++ (SPYXX.EXE) is a Win32-based utility that gives you a graphical view of the system’s processes, threads, windows, and window messages.

Have you ever used Spy++ that comes with MSVC? If you have then you know what Winspector is - but take out all of the annoyances of Spy++ and add in a big bag of handy tweaks and features.

WinCheat is like Spy++ in that it lets you dig deep into the internals of the PE format and the Win32 Windowing subsystems.

WinDowse is an application to analyze the children from a window, result then an efficient and magnific application to analyze the Windows system structure.

vtop is a graphical command-line tool that uses unicode braille to chart CPU and memory usage. It can be easily extended.

https://www.oneperiodic.com/products/processes/

The Extended Task Manager provides additional Windows process management features and information about disk activity and network port usage.

Chameleon Task Manager is Windows task manager that enables the complete control of processes running on a computer optimizing the performance of Windows. It also provides more detailed information about programs.