The TIOBE index ranks popularity of programming languages according to their prevalence on the web. Back in February last year, the R language had risen to #25 in the charts, overtaking both SAS and Matlab. Earlier this month, TIOBE published its annual rankings of programming language popularity for 2011 and R has risen once again: it now ranks #19 in overall language popularity -- its highest ranking since entering the index in 2007. (Matlab is at #23, and SAS at #32.)
According to the TIOBE folks, S and S+ (which preceded R) are also on the list, though not in the top 50. Nonetheless, if you bundled S, S+ and R together, they would rank at #14.
R, a domain-specific language is unlikely to crack the top 10 though, which is dominated by general purpose langauges like C++ and Java. The new #1 fastest-rising language in the rankings is Objective-C, whose popularity is driven by the thriving iOS app market, where applications for iPhones and iPads must be based on Objective-C. The rise of Objective-C since mid-2009 is apparent in this rankings chart of the top 10 languages:
TIOBE Software: TIOBE Programming Community Index for January 2012