Learn two ways to avoid switching on nil in Rails apps, in this double feature from RubyTapas and Upcase
Learn a robust, cross-platform way to throw away unwanted output in Ruby programs.
Learn the twin pillars at the root of the UNIX process-spawning architecture!
Great OOP talks, and the art of avoiding code.
If you're making subprocesses on a UNIX-like OS, you're using fork(). Learn all about using fork() from Ruby.
A few of my favorite non-Gang-of-Four patterns.
"Tell, don't ask" is easy to say, but how do you actually put it into practice?
AMA with Avdi, Part 1
Learn how to make deep copies of arbitrary Ruby object trees.
Freezing a Ruby object can leave you skating on thin ice. Learn how to render complex Ruby objects totally immutable.
Your code is a liability.