ElmerSolver library goes LGPL

Updates in software, documentation, sites etc.
Post Reply
Site Admin
Posts: 3749
Joined: 22 Aug 2009, 11:57
Antispam: Yes
Location: Espoo, Finland

ElmerSolver library goes LGPL

Post by raback »

Dear Elmer users,

The library of ElmerSolver has as from now been published under GNU Lesser General Public license (LGPL). This grants more freedom on how to distribute modules (solver and user functions) that utilize the main library. Even if they are linked with the Elmer library (usually using the "elmerf90" script) they no longer need to be distributed under an open source license as LGPL does not have a viral effect when it is used as a library.

The change covers the ElmerSolver main library (libelmersolver, ~110,000 lines of Fortran code) as well as the libraries matc, hutiter and eio. ElmerSolver library also depends on iso_varying_string that is already published under LGPL. Upon building ElmerSolver may also utilize other libraries that are compatible with LGPL, these include Umfpack (LGPL up to version 5.1.), Hypre (LGPL) and (P)Arpack (Free BSD). Note that if you build Elmer utilizing some more limiting optional libraries you might not be able to use modules that have been distributed in a non-free fashion.

This change does not extend to the existing solver modules, they will still be under GPL. Even the modified versions of these solvers must remain under GPL due to the viral effect. However, if the user creates her own solver from scratch she may license it differently. Also changes to the LGPL library must remain under LGPL license. The change to LGPL does not extend to other programs of Elmer suite (ElmerGUI, ElmerPost, ElmerFront, ElmerGrid and ElmerParam) that communicate with ElmerSolver only via the disk system.

The purpose of the new licensing scheme is to allow flexibility to various development projects that need to combine different licenses. Also it is hoped that a more flexible licensing scheme will increase the overall development efforts in Elmer community which should eventually benefit the whole project. There will be soon a new release numbered 7.0 that will be based on the new license. If you have further questions on how this could affect your use of Elmer software, please contact elmeradm(at)csc.fi for more details.

Best regards,
Post Reply