EnergyPlus™ is open source software. It is distributed under the terms of a permissive, BSD-style license. For more information, see the Licensing page.
Old releases of EnergyPlus (version 7.0.0 through 8.1.0) can be downloaded from the EnergyPlusRelease Github Repository.View Old Releases
Transition utilities are available for updating older EnergyPlus input files to later versions. The files can be downloaded from the Helpdesk.Older Transition Programs