Yihui Xie intended to make it easier to do his homework, but instead found himself tackling one of the greatest problems in modern science: reproducibility of results. Through his work on the knitR package, he has assembled a toolchain which allows the user to produce beautiful, ready-to-distribute documents which contain a whole, self-supporting, and reproducible analysis. In this interview, Yihui discusses how he came to the R programming language and how he set about building knitR. He also mentions the great momentum and energy of the R community in China, and what he’s currently focused on at RStudio.