Subdirectories:
| base | Binaries for base distribution (managed by Duncan Murdoch). This is what you want to install R for the first time. |
| contrib | Binaries of contributed packages (managed by Uwe Ligges) |
| Rtools | Tools to build R and R packages (managed by Duncan Murdoch). This is what you want to build your own packages on Windows, or to build R itself. |
Please do not submit binaries to CRAN. Package developers might want to contact Duncan Murdoch or Uwe Ligges directly in case of questions / suggestions related to Windows binaries.
You may also want to read the R FAQ and R for Windows FAQ.
Note: CRAN does some checks on these binaries for viruses, but cannot give guarantees. Use the normal precautions with downloaded executables.