We are pleased to announce the release of DOCK 6.13. DOCK is a suite of programs for molecular docking. The source code for DOCK 6.13 is available for download and free for academic users at https://dock.compbio.ucsf.edu/DOCK_6/index.htm This release includes new methods for de novo design: new biasing algorithms in DOCK_DN enable the prioritization of both fragments and torsions. Combined with parallel-based clustering and pruning algorithms that enable the efficient removal of duplicate molecules during growth, these approaches lead to ensembles with more drug-like characteristics. A number of incremental improvements are also available in this release notably for DOCK's genetic algorithm DOCK_GA and for Descriptor Score. For full information on what is new in DOCK 6.13, please visit: https://dock.compbio.ucsf.edu/DOCK_6/new_in_6.13.txt Sincerely, The DOCK Team Please visit us at the DOCK Web site. https://dock.compbio.ucsf.edu