This report presents a summary of the results obtained by the ETHZ-LOUVAINMADISON-PSI Collaboration in the search for deviation from maximal parity violation in the Standard Model. These results are confronted to manifest left-right symmetric models, leading to lower limits on the mass of a possible right-handed charged gauge boson. A first generation experiment based on 107 In has been completed in Louvain, while the outcome of the first phase of an experiment based on 12 N at PSI is also presented. In the future the results of the second phase of the 12 N experiment are to be finalysed, and a second generation 107 In experiment is being developped. Finally in the purely leptonic sector, prospects of an experiment measuring the longitudinal polarization of positrons in muon decay are presented.