Found what appears to be a training resource for PowerBuilder today.
What they show on the cover though is an image of a "Power Builder Bee * R Rev Racing Rev Limiter", a device used in high performance cars to cut the ignition during racing when the engine RPM hits the red line.
Perhaps the cover is some sort of joke. I found a "Guide to Password Use in WebSphere Application Toolkit" on the same site that uses a cover from Doctor Who magazine as the image.
Anybody familiar with the product?