Back in the days when I was a Java developer, there was a really hot meme called "dependency injection" (also known in some circles as "inversion of control"). The hype was oriented around the Spring framework, which promised to be the next hotness for developing web apps (amongst other things). It's still around, and doing quite well, but I was seduced by Ruby on Rails before I could really sink my teeth into Spring.
Why am I rambling about this now? Last night when I was trying to fall asleep, Spring floated through my head and I wondered if there was a similar framework for Ruby. Lo and behold, it turns out Jamis Buck constructed a container back in the days before Rails became the web's darling framework.