A while back, I went to a local GoLang meetup to see some quick talks about the Go Programming Language. Keith Rarick gave an interesting talk about godep, a tool to manage dependencies. The regular go tools make it easy to slap together some working code that depends on open-source libraries from elsewhere: the go tools will happily fetch the latest code and build it. But what if you want to re-create that state later and those libraries have changed meanwhile? Once you've figured out a combination of versions that works, you kinda want to hang onto it all in case you need it later.
So far, I've gotten along OK just using the standard Go packages, not using any other libraries. But since my day job involves a lot of thinking about dependencies, this was an interesting glimpse.