EnergyPlus? licenses are intended to encourage the use, improvement, and
widespread adoption of EnergyPlus. Following is information about the
licensing framework for EnergyPlus versions starting at 7.0, which
differs from previous versions in three major ways:
No fee executable distribution license. There are no fees for
use or distribution of EnergyPlus in executable form. You may use the
EnergyPlus executable (either the standalone application or the library),
combine it with other programs, and redistribute it (as either a desktop
application or a web application), for any purpose (commercial or
otherwise) free of charge. Use of this license requires that you refer to
the specific EnergyPlus version as "EnergyPlus vX."
Open source license. For the first time, EnergyPlus is
available under an open source license. Under this license, which is
modeled after the Mozilla Public License (MPL) V1.1, you may obtain
EnergyPlus source code, modify it, combine it with other software that is
licensed under different terms, distribute it, and re-license it. The
license is "weak copyleft" in that it covers only EnergyPlus
and its modifications going forward. Code that is combined with
EnergyPlus is not affected. This license requires that you distribute the
source code for EnergyPlus modifications and that you refer to the
EnergyPlus component of your distribution as "a modified version of
EnergyPlus vX." You may remove the "modified" designation
by obtaining prior written permission from Berkeley Lab. As with any open
source license, there is no fee.
Less restrictive commercial source license. The revised
commercial source distribution license has been relaxed to permit
sub-licensing of proprietary modifications to EnergyPlus. Under this
license, you may obtain EnergyPlus source code, modify it, combine it
with other software that is licensed under different terms, distribute
it, and re-license it. Unlike the open source license, you are not
required to make your modified EnergyPlus source code available; you
retain exclusive control over these modifications. You are still required
to refer to your copy of EnergyPlus as "modified." In the new
licensing framework, this is the only license that requires a fee:
$10,000 US for the first licensed version and $3,000 for major version
updates. Very few scenarios should require this license; the open source
license should suit most purposes. The fee attached to this license is
intended to encourage use of the open source license, while providing
additional rights in cases where they may be needed.
Bug fixes, maintenance releases, and minor version releases of EnergyPlus
will be made available to existing EnergyPlus licensees at no additional
charge on an "if and when available" basis. Obtaining a future
major version release of EnergyPlus will require a new license. The
licensing scheme and fee schedule is subject to change for future
versions.