This work is largely concerned with trajectory tracking in linear complementarity systems (LCS). The main analytical tool for stability analysis and control design is passivity and the associated linear matrix inequalities (LMIs). Cases with and without state jumps, with and without parametric uncertainties, are analysed. Theoretical findings are illustrated with many examples from circuits with set-valued, nonsmooth electronic components, networks with unilateral interactions, and mechanical systems with unilateral springs.