Scientific Libraries in Python

[Kragen Sitaker]

Travis Oliphant <oliphant at ee.byu.edu> writes:
> > As regards the MayaVi license, MayaVi was developed for the community
> > so I didn't want someone to take the MayaVi codebase, use it for their
> > own purposes and not give back anything in terms of code to the
> > community.  That is why I chose the GPL.  However, the GPL does force
> > everyone else who links to it to be GPL.  I guess LGPL might also work
> > but I really don't know.  I'll try to give it some thought.  Anyway, I
> > am not sure you want to put all packages into one huge super package.
> > It would be a nightmare to package/distribute!  I'd really pity the
> > person who'd have to maintain such a beast.
> 
> The LGPL does what it seems like you want you want (doesn't allow people
> to take your particular code, alter it slightly and make it proprietary),
> but it also allows people to release a larger application which only links
> to your code under a non-GPL license.

Right.  Their only obligation would be to let people drop in newer
versions of MayaVi.  So, for example, Mathematica or IDL could add
MayaVi as a plotting option if you released it under the LGPL.

> My understanding is that if you keep the GPL, then folks could build an
> interface, but they could not distribute mayavi with the interface under
> anything but the GPL.

Right.

> That's why I much prefer the LGPL to the GPL for tools which could be
> "hooked together."

And it's why some other people much prefer the GPL to the LGPL for
those same tools.

> Enthought is also interested in distributing an "everything included"
> distribution which contains many of the above packages you mentioned, but
> to distribute such a beast which all worked together dynamically, my
> understanding is that none of the included packages could be GPL (LGPL
> would be O.K.)

That is only the case if some of the included packages are proprietary
or under a GPL-incompatible free-software license.  Does Enthought
want to include proprietary software in their distribution?