present tense

To use a tablet computer comfortably, you have to be able to rotate the screen in all four directions.

Under Windows this is handled nicely by one of three soft buttons to the side of the monitor. You just tap this button with the pen and the screen rotates 90 degrees. Additional taps will keep it going around. Unfortunately these soft buttons are not recognized by Linux, at least not out-of-the-box. However, a relatively simple hack described here makes it possible to do this easily, if not elegantly, under Linux.