You may
Use it, study it, modify it, redistribute it, deploy it — including over a network — and charge for doing so.
Licensing
Free to learn from. Paid to close.
Battery Core is dual-licensed by Lemonergy. The same work is offered on two alternative sets of terms, and choosing one does not affect anyone using the other. If you are here to learn, run it, or build on it in the open, the first one covers you and costs nothing.
Option 1 · No cost
The GNU AGPL, version 3 or later.
Plus one additional term permitted by section 7(b) of that licence: the attribution to Lemonergy must stay visible.
You must
Publish the complete source of whatever you build on it, under the same licence, and keep the Lemonergy attribution visible.
Attribution means
The name Lemonergy in the footer, about screen, or documentation of anything built from this work, and the NOTICE file kept with the source.
No warranty
The licence provides none, by design. If you need a warranty, an indemnity, or support, that is the second option.
Option 2 · By agreement
A commercial licence from Lemonergy.
For anyone whose product cannot meet the two conditions above. Terms are negotiated per case.
You areOK
No payment, nothing to ask
The free licence already covers you
Learning from it, running it, or studying how it works.
Using it unmodified inside your organisation, including on an internal network. Section 13 is triggered by modified versions offered over a network, not by unmodified use.
Teaching with it, citing it, or building research on it, while meeting the licence terms.
Publishing your changes under the AGPL and keeping the attribution.
You needONE
A negotiated licence
Talk to Lemonergy first
Closed product: shipping this inside something whose complete source you will not release under the AGPL.
Hosted service: running a modified version as a network service without offering your users the corresponding source.
Incompatible code: combining it with proprietary code whose licence the AGPL does not permit.
Attribution or warranty: removing or de-emphasising the Lemonergy attribution, or needing a warranty, indemnity, or support commitment.
Getting in touch
Unsure which side of the line you are on?
Ask before you build. It is a short conversation and much cheaper than rework. Say what you are building, whether the code will be modified, and whether it will be distributed or offered over a network — those three answers determine almost everything. Enquiries go to Lemonergy as the licensor, not to any individual maintainer.
Scope
What a licence change cannot do.
Stated plainly rather than left out
Earlier versions keep the licence they were released under
A licence applies from the version that carries it. Versions of this project published earlier under the MIT licence remain available under the MIT licence to anyone who already received them; that grant cannot be withdrawn. These terms govern the versions that carry the AGPL and the Lemonergy notice.
Nothing on this page is legal advice, and this page is not itself a contract. A commercial licence exists once Lemonergy and the licensee sign one.