The Hybrid Identification Toolbox (HIT) is a free MatLab toolbox for regression with Piece-Wise Affine (PWA) maps and identification of Piece-Wise AutoRegressive Exogenous (PWARX) models. HIT implements the clustering-based algorithms documented in some of my papers (see Bibliography.txt in the root directory of HIT). Its development has been supported by the EU projects HYGEIA and HYCON.