Mzabalazo Z. Ngwenya has worked extensively in the field of consulting and currently works as a biometrician.
Yihui Xie (http://yihui.name) is currently a PhD student in the Department of Statistics, Iowa State University. His research interests include interactive statistical graphics, statistical computing, and reproducible research. He is the author of several R packages such as animation, cranvas, formatR, Rd2roxygen, and knitr, among which the animation package won the 2009 John M. Chambers Statistical Software Award (American Statistical Association). In 2006 he founded the Capital of Statistics (http://cos.name), which has grown into a large online community on statistics in China. He also initiated the first Chinese R conference in 2008 and has been organizing R conferences in China since then. He is a co-author of the book Reproducible Research with R (Chapman & Hall), which is under development.