After reading the comments and surfing a bit, I finally found the answer:
How to enable MPX
In case the page goes offline:
Create a new input pair.
xinput create-master New
Show the devices attached to each input pair
xinput list
Reattach devices to the new input pair (replace x and y with the number of the devices from the list)
xinput reattach <x> <y>
Support is built into X, however none of the major window managers are designed with multi-cursor in mind. But it works to some degree.
Here are the window managers i tried:
- Gnome Classic
- Ice WM
- About the same support as Gnome Classic
- Unity
- The second cursor becomes invisible when it's not moving.
- Gnome Shell
- The cursor is invisible all the time, I think it's behind other windows.
- Enlightenment. (My current wm)
- Best of the Window Managers i tried.
- Claims to support multiple focus modes (I couldn't figure out how to enable it)
- Supports dragging of multiple windows at once is strange.
Except for Gnome Shell, all of the window managers handled the multiple cursors pretty well.
I was able to browse concurrently with a friend. However, only one window can be focused at a time. This means one of the keyboards' input is directed at a non-focused (grey title bar) window. For some applications as for example the gnome-terminal, empathy, chrome, this works well, but the blinking text cursor is sometimes invisible.
To which window each keyboards input is directed also seems a bit random. Usually it's the keyboard paired with the cursor that last clicked the window, but not always. And scrolling is sometimes weird.
ICE-MC
I've searched the net for a window manager with better support, and the only thing i can find is a modified version of IceWM called
Multi-Cursor Window Manager (Ice-MC).
It looks like development was abandoned sometime in 2009, and I had a lot of trouble compiling it (some outdated dependencies, I've given up temporarily).
From the screenshots it looks really promising. Each person get's a cursor with his or her own color and the window borders are colored with the color of the person that has keyboard focus. I'll definitely look into it when I have the time.