ggplot2. The 10X was not just that it made it easier and faster to make exceptionally beautiful plots. Rather it was that it made me realize for the first time

ggplot2. The 10X was not just that it made it easier and faster to make exceptionally beautiful plots. Rather it was that it made me realize for the first time that software was, fundamentally, about an implementation of ideas. That the underlying idea, together with how well it's communicated through the API design and documentation, really matters. Reading Wilkinson's description of the grammar of graphics, and then seeing that translated to a code library... That was amazing. It defined what I think software is, as someone who was new to the world coming from an engineering background where coding was just an easy way to do linear algebra.