R (Programming Language)
R is a programming language and free open-source software environment for statistical computing and graphics supported by the R Foundation. It is freely available under the GNU General Public License. R is a highly popular language for programming in statistics in general and bio-statistics in particular.
Language Documentation
R documentation can be found on the official site.
The R Journal publishes open-access, refereed research of interest online.
History
R is considered by many to be a free version of the earlier language S, which was developed at Bell Labs.
Practical Points
The basic data structures of R (vectors matrices, arrays, data frames, etc.) allow for efficient functionality in digital image processing. There are specialized packages in the language related to MRI and PET image processing.