Dear All, I wonder if there is a step by step guide somewhere that will allow me to use Fortran and C codes from packages already on CRAN? I am using Windows XP and "R-2.2.1". I could link to these packages but the problem is that they get updated and they are not backward compatible. Also, I only require a few functions from these packages so it does not seem efficient to load the entire packages every time. Reading the "writing R extensions" and readme.packages leave me rather confused and disoriented, there are bits of information that seem to help, but there also seems to be lots of gap in the process which I have no idea how to fufil. I think these are good documents as a reference guide for people who know what the underlying process is, but not so useful for beginners like me, unfortunately. My question is given I have three C codes (which I can put into one file?) and series of Fortran codes in one file, (and they are already on CRAN), how should I compile it into a dll and make it as part of my package? I have got the command scripts {also from CRAN, extension .R} calling these procedures and I have change the package="name of my package" but where do I go from there seems to be a complete mystery to me at this stage? Any pointers would be very welcome indeed. Steve. [[alternative HTML version deleted]]