This introduction to a pluridisciplinary comparative analysis of European antidiscrimination policies and practices provides a critical assessment of current European empirical developments and the analytical issues that they raise. The authors' argument builds upon the tension between the improvement of the protection of rights to equal treatment and the intensification of xenophobia in the European Union. Can proequality policies developed in a hostile context make a difference? The first part of the introduction provides an analytical framework to account for the emergence and implementation of an antidiscrimination policy framework in the European Union. The second part assesses the limits of this new paradigm in particular as far as the categorization and measurement of discrimination are concerned. It focuses on the broader impact of the development of antidiscrimination policies and jurisprudence and on the way "vulnerable populations" have made use of it.