SoPendulum(3) on Linux
The text c400cb3283ff, as Debian 8 (Jessie) shipped it.
The SoPendulum class is used to create oscillating rotations. A smooth transition between rotation0 and rotation1 is created using a cosine function. In the beginning of the cycle, rotation0 is used. Halfway through the cycle, the resulting rotation equals rotation1, and at the end of the cycle, we're at rotation0 again.