Precompiled Binary Distributions Base system and contributed packages. Windows and Mac users most likely want these versions of R. Linux
MacOS X (10.2.x and above) This version of R for the Mac is actively maintained. MacOS (System 8.6 to 9.1 and MacOS X up to 10.1.x) Last supported version of R is 1.7.1, there will be no more updates.
Windows (95 and later)