If you can read this you are too big to play here.

I remember when I was in preschool I used to climb on a huge tree in the middle of the playground. My friend David and I would catch caterpillars and then squish them on the steps of the school to see what color they were inside. That tree is barely standing now and I've long since realized that squishing things for mere novelty is a little strange. Another thing I discovered later in life was a sign that was hanging from the surrounding fence stating, "If you can read this you are too big to play here".

After my first pass reading this article on InfoQ I had the an all too familiar feeling as if there was something going on that missing me entirely. I read through it a second time and the uses of eval, class/module_eval and instance_eval are starting to become more apparent. Read the code and pay close attention to the use of eval. It might not be so evil after all.