[elephant-devel] Re: Elephant license

[Ben]

Edi,

I'm forwarding this to the list, because it is a discussion users
probably will want to see.

The reason why I chose GPL was 1) it was compatible with sleepycat and
2) I wanted some kind of fair use clause.  But since I use your code
all the time, hey, it's only fair you can use mine!  If you want
something more formal, let me know.

However, it appears that the sleepycat license is incompatible with
your desires, unless you're willing to pay them.  There are some
potential solutions:

Elephant is really 4 pieces: 1) a serializer for general types, 2) MOP
stuff for CLOS types, 3) collection classes, and 4) a back end
(currently FFI bindings to sleepycat.)

1) Conceivably one could swap out different back ends.  I thought
about trying to do this for SQLLite or Firebird.  This would be a bit
of work but it wouldn't be that hard, just time consuming.  I think
  the sleepycat.lisp / berkeley-db.lisp files should be a good model.
The only requirement for the back end is that they have sequences and
be able to store byte arrays.  However, if you want niceties like
sorted btrees (esp in the presence of Unicode+bignums), there will be
some work to get that to work.

2) Write an all-Lisp back end.  There are many possible approaches
here: transaction log in one file, ala ZODB FileStorage, or use the
underlying filesystem btree and do something like ZODB
DirectoryStorage, or recreate WOOD.....this seems hard to get right.
I was originally going to do this when I started writing elephant, but
decided against it, for that reason.

3) Pay sleepycat.  I don't know how much they cost.

Here's the caveat -- I don't have time to make these kinds of changes.
But I'm certainly willing to advise.

CLSQL appears to have some kind of MOPish framework.  It has a decent
license too right?

take care, B

On Mon, 28 Feb 2005, Edi Weitz wrote:

> Hi!
>
> In the "LICENSE" file from Elephant it says
>
> "For differenct licensing terms, contact the copyright holders."
>
> so here I am... :)
>
> I've looked at Elephant and it seems to be nice.  However, I noticed
> that the license is the GPL and from my understanding this means that
> if I write a Lisp application for a customer of mine which uses
> Elephant then the whole application has to be under the GPL as well
> which is not an option for me.
>
> My question is: Would you consider releasing Elephant under a
> different license like LLGPL or BSD?  And if not would you consider
> offering a dual-license model where one can pay for the right not to
> open source code based on Elephant?
>
> Also, do you have any experience with SleepyCat's licensing model?
> Would I need to pay for a SleepyCat license as well or is that covered
> by Elephant's open source license?  (I'm sending the same question to
> them but maybe you know this already.)
>
> My apologies if this has been dicussed before.  I briefly searched the
> mailing list archives but couldn't find anything related to this
> question.
>
> Thanks for your help,
> Edi Weitz.
>
> -- 
> Dr. Edmund Weitz
> Hamburg
> Germany
>