Regarding Rcpp, their package library says "A Renjin-specific version of this package is available."[1]

Looks like Renjin can also be used from GNU R as an R package[2]. I'd assume any installed R package should also work in conjunction with it.

Admittedly, I haven't tried Renjin, but only just found it and thought it was quite interesting.

[1] http://packages.renjin.org/package/org.renjin.cran/Rcpp

[2] http://docs.renjin.org/en/latest/package/index.html#using-re...