Version: (using KDE KDE 3.3.2) Installed from: Slackware Packages When holding Shift, the scroll wheel should function left-to-right instead of top-to-bottom. This functionality exists in Mac OS-X and it is an incredibly useful feature. (Currently, shift+scrollwheel scrolls more swiftly, ctrl+scrollwheel changes text-size, and alt+scrollwheel does nothing. I recommend shift+scrollwheel as opposed to alt+scrollwheel for the sake of giving users an easier migration between systems and because the shift key is a larger target and as such should be used for the more important functionality.)
Alt+ScrollWheel can be used to scroll horizontally in 3.4 and newer versions of KDE.
Is it not possible to include a setting to specify the modifier key for horizontal scrolling? :( I have a problem with the Alt key being the modifier, I use it to change the opacity of windows, so when I horizontal scroll the opacity is also affected. This is also the case with kolourpaint. Shift+scroll is used in lots of places like google chrome, many places in ubuntu unity and others.
It would need to be changed in the Qt toolkit.