To install `flan` from GithUb,  Windows users need to follow these steps:

1- Make sure that there are no spaces in the path of R. For example, "C:/Program Files/R" can not be used;

2- Install Rtools;

3- Download local323.zip file at http://www.stats.ox.ac.uk/pub/Rtools/goodies/multilib/
and extract it (in C:/R/local323/ for example). Again, make sure that there are no spaces in the path.

4- Create the environment variable LIB_GSL with value the path of the directory local323 (C:/R/local323/ for example)