Process Hacker is an astoundingly useful and full-featured tool for monitoring and, yes, hacking ongoing processes on your PC. There is an astonishing amount of functionality crammed into a clean, well-designed, interface. And it's free.
When I first found this software, I admit to a bit of eye-rolling. "Great, someone else tossed a quick skin on something Windows includes for free and thinks he's made something useful." I was very, very, wrong.
Process Hacker is to the included Windows "Task Manager" what a 747 is to a three-year-old with a towel around his neck about to learn a painful lesson about gravity. Even if Process Hacker were limited to just the information it shows in the main GUI--such as a hierarchy of which processes are owned by which applications, which services are in which SVCHOST, and (if you want to turn it on) a graph for each service of its CPU usage--it would be worth downloading. However, it goes far beyond even that.
Right-click on a process, and you get a huge list of options, one of which is the seemingly trivial "Properties". This menu item, though, opens the doorway into a realm of more data than I knew existed. Nine subtabs await you, some with tabbed pages of their own, detailing everything from the security privileges the process is allowed (Microsoft Word, for example, is not permitted to shut down someone else's computer). Further, and this is very cool indeed, Process Hacker can show you the memory a process uses--not how much memory (it does that too, in detail) but the contents of it, and you can copy or edit it. Note: Editing memory of running processes can be very, very, dangerous. This feature is mostly useful for programmers looking for obscure bugs, or checking for security flaws.
Process Hacker lets you do things that are difficult to do in Windows proper. For example, it can scan for, and kill, hidden processes. This feature is only available on 32-bit systems, due to security limits on 64-bit systems, but it's useful because it can reveal viruses, spyware, or undocumented Windows processes.
Flaws are few. Process Hacker is mostly stable, but I did experience a crash when doing some memory searches. As is perhaps fitting, this program tends to assume you know what you're doing--help is functional but sparse. The FAQ includes some other warnings about known bugs and issues. Process Hacker offers tremendous power to change things few users should be changing; this isn't a flaw, but it does mean that even geeks should proceed with caution.
If Task Manager makes your eyes glaze over, Process Hacker isn't for you. If you're a system administrator, a programmer, or a hacker in the noble sense of the word--a person who wants to know all there is to know about a system, including getting down and dirty with the bits and bytes--this tool may prove more of a timesink than tvtropes.org. I haven't mentioned a tenth of the cool things I found while testing this program. Too many free programs are overpriced, this is freeware which would be worth paying for--a rare thing, indeed.