The term 'R Followers' refers to people who are devoted to the programming language R. R is a free software environment for statistical computing and graphics, and is widely used by data scientists and statisticians. The two crossword solutions for this term are STU (3 letters) and STUV (4 letters). STU stands for 'Statistical Tools for Users', which is a group of packages that provide a wide range of statistical tools for users of the R language. STUV stands for 'Statistical Tools for Users and Visualization', which is an extension of the STU package that provides additional tools for visualizing data.