Testing
I think it's quite impressive how software testing has grown in popularity in the past decade. A lot of tools (open-source and commercial) and practices such as continuous testing and integration, code coverage, static analyzers and so forth. Some of that fancy stuff you've probably heard about, they were originated, disseminated and now getting lift from agile development processes "spaceship" (e.g.: Extreme Programming, Scrum and so on). But, the agile methodologies' boom is a topic for another talk. ;)
