Data frame support has been added to the package RcppTemplate 4.0, a template/class library that facilitates the use of C++ libraries from R. On the C++ side the code might look something like: RcppFrame frame(fp); // Here fp is the input SEXP corresponding to an R data frame. vector<vector<ColDatum> > table = frame.getTableData(); ... level = table[row][col].getFactorLevel(); name = table[row][col].getFactorName(); ... Thanks to Hin-Tak Leung and other users of this mailing list for helpful comments. The RcppTemplate package also contains detailed instructions on using MinGW and MS Visual C++ under Windows. ds