Welcome to Erhard Wielandt's website for free seismological software

This is free software for practical use, especially for the design, calibration, and testing of seismographs.
Copyright 1970-2015 by Erhard Wielandt. You can use these programs, modify them,
and redistribute them under the terms of the GNU General Public License as published
by the Free Software Foundation, either version 3 of the License, or any later version.
Find more details here .

This collection also contains educational software and figures used in courses and
workshops, and a few manuscripts on wave propagation and seismometry.
Everything is offered in the hope that it will be useful, but WITHOUT ANY WARRANTY.
If you are interested in software, please read the software overview first.