Somewhat unfortunate naming as it may be confusing with the FAIR Principles (Findable, Accessible, Interoperable, Reusable), for which software package managers are emerging as well.
Must be a late entry.. Unfortunatel the WIL metric overlaps in name with Written in Lisp:
Additionally we propose two new metrics. The Written in Latex (WIL) metric is the proportion of source code of a machine learning library written in LaTeX and the Source code of method in source code of paper (SCOMISCOP) metric is the proportion of the source code of a method that is contained within the source code of the paper.