[Rd] Using Fortran 90 code in packages for CRAN

[Lukas Lehnert]

I recently submitted a package to CRAN which encompasses Fortran 90 code. 
Neither on my linux system nor on the win-builder system the compilation 
reported any error or warning. The function worked fine. However, after 
submission of the package to CRAN, I received an email that I should not 
include Fortran 90 code. 

The problem is that the part written in Fortran is a large function using 
modules. Thus, rewriting the function in FORTRAN 77 is  impossible. So, I 
searched on CRAN and found some packages which contain Fortran 90 code. Is it 
generally possible to submit R packages to CRAN containing Fortran 90 source 
code? If so, what specific things should I consider?

Thank you for your help 

Lukas Lehnert