Professor Tangent Popups
Enable popups to browse faster without losing your place. Selecting "popups"
from the menu at the left side of each main page displays each link in a
movable, resizable popup window instead of replacing the current page. You
might have to adjust your browser settings or click on a status bar to tell
your browser to allow popups. The screen shot is a sample of what the
screen looks like with popups selected.