Thinking about Kent Beck and Extreme Programming have gotten me thinking about some great quotes I've heard from him over the years. Some that come to mind are:
An audience member asks: "Can you prove that XP scales to work on large projects?" Kent responds: "Can you prove your favorite heavyweight methodology does?" Touche!
"Reuse is easy. Just separate the part that changes from the part that doesn't."
"There are only two ways to improve some code's performance: Make it do fewer things, or make those things go faster."
In a discussion about TDD, an audience member asks: "Isn't building all of those tests a hassle and unnecessary? They're not part of the product you ship to customers." Kent responds: "The same can be said for the scaffold used to build a building. Once the building's complete, you dismantle the scaffold. Therefore, if you could build the building without building the scaffold as well, that'd be a lot easier. But until there's a way to do that, the scaffold is necessary too."
I also remember a very simple quote from Ward Cunningham: "You have to stop and ask yourself: 'What's the simplest thing that could possibly work?'" When I heard this back in the mid-1990s, little did I know that this nugget of truth would become the foundation for XP.