Kaleidoscope Pen

Here is a pictue of the kaleidoscope pen, that writes the same thing four times mirroring in each quadrant.

Despite the fact that delegation languages are much simpler than class-based languages, having replaced inheritance, overriding and classes with a single concept, most people find delegation languages rather unnatural, and the idea has not ever caught on widely.

[audio] [real] Text to accompany slide14, in Chapter 20 of An Introduction to Object-Oriented Programming