Rtools 3.5 can be downloaded from our website for free. The most popular versions of the software are 3.1, 3.0 and 2.9. The program is included in Development Tools. Our antivirus scan shows that this download is malware free. Rtools is developed for Windows XP/Vista/7/8/10 environment, 32-bit version. The program's installer files are generally known as OTMClient.exe, OTMLancher.exe or updater.exe etc. This free program is an intellectual property of The R Foundation.
From the developer:
R is ‘GNU S’, a freely available language and environment for statistical computing and graphics which provides a wide variety of statistical and graphical techniques: linear and nonlinear modelling, statistical tests, time series analysis, classification, clustering, etc.
You may want to check out more software, such as Erlang, Multimedia Fusion 2 or Mono for Windows, which might be related to Rtools.