If you need to scroll an application window on a PC then spinning the mouse wheel is probably the simplest route. This only works on the foreground window, though, the one where you’re currently working. And so if you want to scroll some other window, you must click it first.
AlwaysMouseWheel is a tiny portable tool which changes all this. Once running, you can switch to and scroll any window Ubuntu-style just by moving the mouse cursor over it, and spinning the wheel -- no extra click required. It’s a small improvement, but if you regularly work with a lot of open applications then it can make a real difference.
It’s possible to achieve something like this without installing any extra software at all, of course. Open the Ease of Access Center applet in Control Panel, select "Make the mouse easier to use" and check "Activate a window by hovering over it with the mouse". You can then switch to any window just by pointing at it.
We find the Ease of Access solution to be a little too drastic, though, as it becomes very easy to accidentally switch between open applications. You then have to move the mouse back to your preferred window, and the extra effort more than cancels out any clicks you might save.
AlwaysMouseWheel's extra control means it wins out for us, then. And its extreme portability is a plus, too: the author claims it runs on any version of Windows from 98 upwards, so if you like this way of working then you can take the program with you and use it anywhere. Go take a look.