I'm new to Mac OS X. Sometimes my system hangs, and I cannot do anything with it. In Windows, I would use Task Manager to stop the unwanted application, but in Mac OS X, what option is available? When my Mac has hung, I have used "Activity Monitor" only. Are there any other options available in Mac OS X?
If you just want to kill hanging apps try pressing cmd+alt+esc. This opens a mini version of activity monitor, which allows you to select and kill any hanging applications.
You want to use Activity Monitor in your /Applications/Utilities folder. This is the equivalent of Windows Task Manager. It will give you a full list of all processes running on your computer at that time, importantly the ones running in the background. However, be careful what you decide to kill because it can make your system temporarily unstable (requiring a reboot) if you don't know what you're doing.
You can right-click on the icon of a running/hanging application in the Dock. If it is not responding, the usual Quit is turned into Force Quit. If the program is running fine, but you want to force quit anyway, hold alt.
I used the Terminal with the command
top -o vsize to see wich program is consuming more memory, then i killed with
kill PID or
killall PROGRAM. I like these because is lighter than Monitor Activity.
in Terminal application you can type
to list all the processes. each one has a pid which you can stop by typing
replacing pid with the actual process number
I like to add a link to iStatMenus. It shows cpu, ram consumption, disk usage and a lot more in the menubar.
(It's a shame that isn't integrated in Mac OS X)
You can use Activity Monitor i.e. Mac Task Manager. There are many ways to do it. Easiest one is just type activity monitor on spotlight search.
If you wish to learn more about Mac activity monitor then check out: How to use mac activity monitor?