HepMC2 release main purpose: fixes in xAOD common fragments contains MRs: https://gitlab.cern.ch/atlas/athena/-/merge_requests/61640 Minor fixes for xAODDecaysFinalStateFilter https://gitlab.cern.ch/atlas/athena/-/merge_requests/61619 Use where possible access by const reference for MC objects https://gitlab.cern.ch/atlas/athena/-/merge_requests/61638 Remove boost from EvtGen https://gitlab.cern.ch/atlas/athena/-/merge_requests/61770 Remove unused boost string headers https://gitlab.cern.ch/atlas/athena/-/merge_requests/61769 Remove unused lexical_cast headers https://gitlab.cern.ch/atlas/athena/-/merge_requests/61818 GeneratorObjects: c++20 fix https://gitlab.cern.ch/atlas/athena/-/merge_requests/61747 Use ReaderFactory for the ascii file input https://gitlab.cern.ch/atlas/athena/-/merge_requests/61850 GeneratorObjects: Fix thread-safety checker warning. https://gitlab.cern.ch/atlas/athena/-/merge_requests/61898 AtlasHepMC: Missing const qualifier. https://gitlab.cern.ch/atlas/athena/-/merge_requests/61886 EvtGen_i CMake Fix, 23.0 branch (2023.03.27.) https://gitlab.cern.ch/atlas/athena/-/merge_requests/61671 Implementation of non-currently-supported decays in gg4l process via change of pdg ID in LHE files https://gitlab.cern.ch/atlas/athena/-/merge_requests/61725 GeneratorFilters: Update xAODJetFilter_Common.py