Analyst firm RedMonk have updated their (near-)biannual Programming Lanuage rankings as of January 2016, and the R language ranks at #13, unchanged since the last ranking in June 2015. Redmonk's rankings are based on number of projects in GitHub and number of questions tagged in StackOverflow, and the most recent data is visualized (using R's ggplot2 package) below:
In this latest RedMonk ranking, Python is likewise steady at #4, and Matlab falls one place to #18. See the entire list and a new visualization of ranking changes over time here: RedMonk Programming Language Rankings: January 2016.
Meanwhile, the Tiobe Index for February 2016, which ranks languages according to search engine results, places R at #17 (up 1 places from a year ago). In the same Tiobe rankings, Python places at #5, Matlab at #18, and SAS at #12.
For more R rankings from these and other sources, check out the popularity section of the blog.