We have started working on a new rOpenSci package called writexl. This package wraps the very powerful libxlsxwriter library which allows for exporting data to Microsoft Excel format.
The major benefit of writexl over other packages is that it is completely written in C and has absolutely zero dependencies. No Java, Perl or Rtools are required.
Getting Started The write_xlsx function writes a data frame to an xlsx file. You can test that data roundtrips properly by reading it back using the readxl package.