For ultimate flexibility, Scheme provides the ability to make your own language constructs using macros. Andy Balaam shows how to use them, takes us through an example, and compares the Scheme way with how you might do something similar in C, JavaScript, Python and Java. If you're new to Scheme, try http://youtu.be/byofGyW2L10 first. The slides for this video are here: http://www.artificialworlds.net/blog/2012/07/02/scheme-7-macros-video/