My teaching style is unusual within Computer Science. I do not use presentation software like PowerPoint. I teach using the white board. I believe that teaching and learning are interactive processes that require give and take between the instructor and the students. Hence, I insist that students be active learners in my classroom. They take notes, and they pose and answer questions. They are not merely passive observers. To lecture in the dark is invite students to slumber the class time away! Not only does light help engage students, the whiteboard facilitates creativity in the classroom in ways software presentations do not. The whiteboard naturally fosters classroom interactions that are not static---adhering to a rigorous pre-defined agenda---but rather, they can be dynamic in that they can accommodate interesting digressions; and they can be non-linear, that is, the instructor can easily build on material presented any time during class, not only on the last few slides. In contrast, PowerPoint presentations often fail to support interactive learning.