Standard license agreement of Söngen Development GmbH

Version 3 from August 1, 2020. PDF version.
Please note that only the German license text is legally binding; the following English translation of the German license text is not legally binding.

This license agreement determines the terms under which we, Söngen Development GmbH (Georg-Müller-Str. 2, 65347 Eltville am Rhein) license our software to the acquiring party of this license (you).


Within this license agreement we refer to the (minified) JavaScript source code of our software Kontrast including all necessary files that ensure its correct function as library.

We refer to the library, the examples and the documentation as the software.

We refer to an installation as the permanent storage of our software or of parts of our software on a permanent storage device. This does not include the temporary storage of our software or of parts of our software as the result of a web browser loading a web site that uses our software.

We refer to any person who uses the software interface of our library as developers (this includes creating interactive visualizations using our software).

We refer to any person who views and manipulates an interactive visualization that uses our software as user.

Ownership and copyright

The software is licensed under the terms of this license agreement. The owner of the software is Söngen Development GmbH. The copyright holder is Söngen Development GmbH. We reserve all rights that are not explicitly granted in this license agreement. The software must not be modified. We grant the right to use our software under the following terms.

Installation and usage

We offer single-user and multi-user licenses. Both types of licenses allow to use our software for an unlimited amount of time.

Single-user license

A single-user license permits you to install the software on all devices that are used exclusively by you and where it is ensured that only a single installation of the software can be used at any given time. A single-user license holder may use the software both as developer and as user.

Multi-user license

A multi-user license allows you to install the software on any device, if you ensure that at maximum the number of the users specified when purchasing the software has access to these installations as developers. A multi-user license allows the number of persons specified during purchase to use the software as developer and user.

Publication for non-commercial purposes

You may publish interactive visualizations that are based on our software including all necessary files to ensure the proper function of your interactive visualization under the condition that the publication only serves non-commercial purposes. In any other case, publication is not permitted.

Updates and support

You may download and use updates of our software within a period of one year (starting with the date of purchase) free of charge. Within this time period of one year we will respond to technical support inquiries within 36 hours on workdays.


You may create backups of our software on other devices, if the sole purpose is the recovery of our software in case of data loss.


We ensure the correct functionality of our software according to the advertised functions and we ensure that our software is state-of-the-art without faults within a warranty period of one year. Only after we fail to fix faults within our software after an appropriate time you are granted the right of contract avoidance or price reduction.

Exclusion of liability

We are only liable for defects of title or intent or gross negligence. All other liability is excluded – independent of its nature – particularly for loss of data or consequential damages.

Applicable law and venue

This license agreement is governed by and construed in accordance with the laws of Germany. Any dispute arising out of this agreement shall be settled at the court at the registered office of Söngen Development GmbH.