Normality, Ordinary Least Squares (OLS) and Geographically Weighted Regression (GWR)

Most of the publications I have reviewed, conduct both OLS and GWR for comparison, and prior to analysis, ensure dependent and explanatory variables are normally distributed. Can someone explain why this is necessary for GWR? Are both OLS and GWR parametric? Is there a non-parametric version of GWR?