We present here a new version of the Arlequin program available under three different forms: a Windows graphical version (WINARL35), a console version of Arlequin (ARLECORE), and a specific console version to compute summary statistics (ARLSUMSTAT). The command-line versions run under both Linux and Windows. The main innovations of the new version include enhanced outputs in XML format, the possibility to embed graphics displaying computation results directly into output files, and the implementation of a new method to detect loci under selection from genome scans. Command-line versions are designed to handle large series of files, and ARLSUMSTAT can be used to generate summary statistics from simulated data sets within an Approximate Bayesian Computation framework