Re: [libreplanet-discuss] Can we licence our Clojure (Eclipse Public License 1.0) project with the GNU AFFERO GENERAL PUBLIC LICENSE?

[Aspasia Beneti]

Hi Aspasia,

Great to see you reaching out on this topic. Perhaps you can write on
your findings, for all Clojure developers to take note? As you know I'm
not developing under a free software license at work, but I did look
into this topic as a Clojure developer. I specifically looked into the
GPL, not even the AGPL. Let me break down your question to the
different topics:
> Thanks! I will make sure to share any findings on this subject.

JVM
It seems the GNU Classpath was used at the start of OpenJDK, but later
all was upstreamed to the OpenJDK project.[1] OpenJDK is licensed under
the GPL, but with a linking exception for the classpath.[2] So I don't
think the JVM blocks AGPL adoption.
[1] https://en.wikipedia.org/wiki/OpenJDK#IcedTea_and_inclusion_in_soft
ware_distributions
[2] https://en.wikipedia.org/wiki/OpenJDK
> Yes, thats my understanding as well

Libraries
Going through your dependency list [0], I notice different licenses:
EPL 1.0:  Clojure, Timbre, Liberator, Autoclave, most others
MIT:  Ring, Cheshire
EPL 1.0 & Apache 2.0:  Monger
AGPL 3.0:  FXC (Dyne.org project)
(I didn't look them all up)
[0] https://github.com/PIENews/freecoin/blob/master/project.clj

If I understand correctly, the linked libraries do effect the license
compatibility, so the EPL/AGPL conflict is a real issue here.

> I thought that for instance the Clojure.jar could fall under the “System 
> libraries” exception but you are right. Even then, what about the rest? 
> That’s an interesting related discussion 
> https://groups.google.com/forum/#!topic/clojure/9yzj2vTVSok

Macros
As a lisp, Clojure uses macro's to modify the code at runtime. Then
again, the macro's are code as well, so they'll also have a license
attached to them. Maybe issues arise when the code is AGPL, but the
macro modifying the code is EPL. To be fair, you shouldn't be using as
much macro's anyway ;)
> We are not using any at all as far as I know. However, from a legal point of 
> view I can imagine that the possibility of using them is enough.


The long game would be to have a AGPL-friendly lisp platform, with
similar semantics to Clojure. This could be another reason why you'd
want to avoid copyleft or dual-license any libraries you put out on
Clojure.
Projects I have looked into:
- GNU Guile: Distant from Clojure, but a GNU project.
- hylang.org: MIT-licensed Clojure-inspired lisp based on Python, by
modifying the Abstract Syntax Tree.
- Pixie: Clojure-inspired lisp based on RPython with C-interop.
> Thanks for the suggestions, I will have a look. However I have to say that we 
> are extremely happy with Clojure so far and we would like to make it work.

I hope others can chip in to share their view, as there are probably
others asking a similar question.

Kind regards,
Nico Rikken (NL, FSFE)

Aspasia Beneti aka aspra
Dyne.org Think & Do tank
Lead software developer of the Freecoin toolkit
GPG: 204F 8156 8C0E 0600 E17C  001B 58D2 05D8 7EE4 D9F4