OpenSees is an open-source software platform for simulating the behavior of structural and geotechnical systems subjected to earthquakes and other forms of dynamic loading.
It can be used by engineers, researchers, and students to perform nonlinear dynamic analysis of structures and soils. OpenSees provides a convenient and efficient interface for formulating, solving, and visualizing the results of complex dynamic models, and it supports a wide range of modeling approaches and numerical methods.
The software is Copyright @ 1999-2020 The Regents of the University of California (The Regents). It is free for anybody to use, with the exception being that if you sell software that includes OpenSees source code you must obtain a license to do so from UC Berkeley, and like all software you use at your own risk. That license in all it’s legal glory:
Copyright @ 1999-2020 The Regents of the University of California (The Regents).
All Rights Reserved.
The Regents grants permission, without fee and without a written license agreement, for (a)
use, reproduction, modification, and distribution of this software and its documentation by
educational, research, and non-profit entities for noncommercial purposes only; and (b) use,
reproduction and modification of this software by other entities for internal purposes only.
The above copyright notice, this paragraph and the following three paragraphs must appear in
all copies and modifications of the software and/or documentation.
Permission to incorporate this software into products for commercial distribution may be
obtained by contacting the University of California
Office of Technology Licensing
2150 Shattuck Avenue #510,
Berkeley, CA 94720-1620,
(510) 643-7201.
This software program and documentation are copyrighted by The Regents of the University of
California. The Regents does not warrant that the operation of the program will be
uninterrupted or error-free. The end-user understands that the program was developed for
research purposes and is advised not to rely exclusively on the program for any reason.
IN NO EVENT SHALL REGENTS BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL,
OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE
AND ITS DOCUMENTATION, EVEN IF REGENTS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
REGENTS GRANTS NO EXPRESS OR IMPLIED LICENSE IN ANY PATENT RIGHTS OF REGENTS BUT HAS
IMPLEMENTED AN INDIVIDUAL CONTRIBUTOR LICENSE AGREEMENT FOR THE OPENSEES PROJECT AT THE
UNIVERISTY OF CALIFORNIA, BERKELEY TO BENEFIT THE END USER.
REGENTS SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE AND
ACCOMPANYING DOCUMENTATION, IF ANY, PROVIDED HEREUNDER IS PROVIDED "AS IS". REGENTS HAS
NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
Redistribution and use in source and binary forms, with or without modification, are
permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright notice, this list of
conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice, this list of
conditions and the following disclaimer in the documentation and/or other materials provided
with the distribution.
* Neither the name of the copyright holder nor the names of its contributors may be used to
endorse or promote products derived from this software without specific prior written
permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
