Open Web Index Licence (OWIL) – Version 1.0

Last Updated: May 8th, 2024


To promote an open human-centred search engine market and provide a solid basis for building front ends for offering a true choice to internet users in selection of preferable search engines, OpenWebSearch.EU develops and pilots the core of a European Open Web Index (OWI). It is the foundation for an open and extensible European Open Web Search and Analysis Infrastructure.


“Index Data” – The Index Data consists of processed web data derived from previously crawled web data. They are processed in a way that they serve as basis for search applications and web search engines. Hence, they consist of a search index (list of terms and related web documents) and meta data of the original web documents including the plain texts and processed information. The Index Data is distributed over several data centres and organised in partitions.

“Index Service” or “Service” – The Index Service is a software application that allows access to the Index Data through a Web Interface or an Application Programmable Interface (API). It allows to get information of the index data, as well as to download parts of the index (“index partitions”). 

“Open Web Index” (OWI) – The Open Web Index consist of both the Index Data and the Index Service. 

“Open Web Index Partition” or “Index Partition” – The Index Partition is a part (subset) of the Index Data that can be downloaded and used to create an own search application. 

“Licensor” – For the purposes of this Licence, “Licensor” refers to Universität  Passau, located at Innstraße 41, 94032 Passau, Germany. The Licensor acts on behalf of the consortium (OWSEC), a collective  initiative aimed at advancing open web search technologies and  infrastructure. References to the Licensor within these Terms encompass  both Universität Passau in its capacity as a participating institution  and the broader objectives and activities of the  consortium.


The OWI as a prototype remains under active development within the project (Horizon Europe project – GA 101070014), with its various features, content, and underlying technologies still being refined and implemented for the realization of its full potential. The consortium (OWSEC) is committed to regularly updating the service with iterations that introduce work-in-progress functionalities and improvements essential for the maturation of the Open Web Index. As a result of this continuous development process, the users may encounter inconsistencies, incomplete features, temporary limitations, or down-times. Access to and use of the OWI is provided “as-is,” and is subject to change or termination without notice The consortium appreciates your understanding and patience, as the consortium works towards enhancing the Open Web Index to meet and exceed expectations in future updates.

  1. Acceptance of Terms

By using the OWI and/or index partitions, you agree to be bound by these Terms of Use (“Terms”). If you do not agree to all of these Terms, do not use this Service!

Nothing in these Terms limits or excludes OWSECs liability for anything that cannot be excluded by applicable law. Subject to the foregoing, to the fullest extent allowed by applicable law, you expressly agree that the use of the OWI, related websites, or any associated services is at your sole risk. The OWI and all related content and services are provided on an “as is” and “as available” basis for your use, without any warranties of any kind, either express or implied, unless such warranties are inapplicable for exclusion by law. In such cases, these warranties are excluded to the maximum extent permitted by law. The OWI is provided on a research purpose basis and there are no guarantees regarding the suitability for a particular purpose, or the availability and accessibility of the OWI at all times or in specific geographic areas. The use of the OWI is at your sole risk.

  1. Use of Open Web Index (OWI)

a. You agree to use the OWI only for lawful purposes and in a manner that does not infringe the rights of or restrict or inhibit the use and enjoyment of the OWI by any third party. Any violation may lead to the immediate termination of your right to use the OWI. 

b. As of now the OWI is provided for personal, non-commercial use, research purposes an personal use only.

c. Users of OWI are required to prominently include a disclaimer in any and all presentations, applications, or services that are built upon, utilize, or otherwise incorporate said derived index partition. This disclaimer must clearly state that the service, application, or presentation has been developed using an index partition derived from the OWI and must at least contain the following information: 

“This work uses index files as part of the index partition created by the project that has received funding from the European  Union’s Horizon Europe research and innovation programme under grant  agreement No 101070014 (OpenWebSearch.EU).”

  1. Intellectual Property Rights

Any content made available through OWI is the property of their respective owners. Your access to and use of this content is subject to the terms and conditions set forth by these owners. By using this OWI, you acknowledge and agree:

  • to respect and adhere to all applicable intellectual property rights, 
  • and to use the content strictly in accordance with the respective terms and conditions of each owner 
  • well as by to respecting all technical implementations that restrict the way in which content included in the OWI may be used such as the use of robots.txt.

Furthermore, your use of the content provided through OWI must also comply with all relevant rules and regulations, including but not limited to copyright laws, trademark laws, and any other applicable intellectual property legislation. You are responsible for ensuring that your use of the content does not infringe upon the rights of the content owners or violate any laws. Any unauthorized use, reproduction, distribution, or modification of the content is expressly prohibited and may subject you to legal action, including but not limited to civil and criminal penalties.

It is your responsibility to familiarize yourself with and adhere to the specific rules, regulations, and terms set by the content owners. This includes, but is not limited to, obtaining any necessary permissions or licenses required for the use of copyrighted or proprietary content. OWSEC provides no warranties or guarantees regarding the legality or appropriateness of the content for any particular use, and it disclaims any liability for unauthorized use of the content accessed through the Service.

  1. Disclaimer of Warranties

a. OWI is provided “as is” and “as available” without any warranties of any kind, including the implied warranties of merchantability, fitness for a particular purpose, or non-infringement.

b. OWSEC does not guarantee the accuracy, completeness, or usefulness of any information on the Service and does not adopt, endorse, or accept responsibility for the accuracy or reliability of any opinion, advice, or statement made by parties other than OWSEC.

  1. Limitation of Liability

You as the User acknowledge and agree that, except as outlined in these Terms and to the fullest extent permitted by applicable law, OWSEC, its licensor, and affiliates are not liable for any act or failure to act by them or any other party regarding conduct, communication, or content on the services. In particular, they shall not be liable to you for any direct, general, incidental, special, or consequential damages, including loss of profit or revenue, arising from (i) your access to, use of, or inability to access or use the Service; (ii) any conduct or content of any third party on the Service, including without limitation, any defamatory, offensive, or illegal conduct of other users or third parties. In no event shall the liability of OWSEC, its licensor, affiliates, employees, officers, or directors to you exceed the amount that you have paid for the services.

  1. Indemnification

You agree to indemnify and hold harmless OWSEC from and against any claims, administrative fines, damages, obligations, losses, liabilities, costs, or debt, and expenses (including but not limited to attorney’s fees) arising from: 

  • your use of and access to the Service including the use by people under your direct supervision; 
  • your violation of any term of these Terms; 
  • your violation of any third-party rights, including without limitation any copyright, trademark, privacy, or other proprietary rights; or 
  • any claim that your use of the Service caused damage to a third party.
  1. Modifications to Terms

OWSEC reserves the right, at its sole discretion, to modify or replace these Terms at any time. If a revision is effective, the consortium will provide at least 14 days’ notice prior to any new terms taking effect. What constitutes a material change will be determined at OWSECs sole discretion. If you do not agree to the modification and/or replacement further use of the Open Web Index is no longer possible. 

  1. Revocation and Termination

The OWSEC, as the Licensor, reserves the right to terminate this License and revoke your access to the OWI at any time and for any reason. Such revocation may be executed with or without notice at the sole discretion of OWSEC. Reasons for revocation may include, but are not limited to, breach of any terms and conditions of this License, misuse of the OWI, legal or regulatory reasons, or any other actions deemed harmful or inconsistent with the interests or policies of OWSEC.

Upon termination of this License, whether by revocation by consortium or other means, the Licensee must immediately cease all use of the OWI and destroy all copies, full or partial, of the data obtained from the OWI in their possession or control. The Licensee must confirm in written form to OWSEC that they have complied with the above requirements within seven (7) days of the termination notice. Any use of the OWI after the termination of this License is unauthorized and may subject the Licensee to legal action. The Licensee acknowledges that OWSEC shall not be liable for any damages, losses, or liabilities suffered by the Licensee due to the termination of this License. The obligations of the Licensee under this clause shall survive the termination of this License.

  1. Governing Law

The licensee hereby agrees that all disputes arising out of or in connection with this license shall be governed exclusively by the laws of Germany, expressly excluding the application of its conflict of law provisions. All disputes arising out of or in connection with this license shall be subject to the jurisdiction of the competent courts in Munich, Germany

  1. Severability

If any provision of these Terms is held to be invalid or unenforceable by a court, the remaining provisions of these Terms will remain in effect.

  1. Waiver

If OWSEC fails to exercise or enforce any of the rights covered in these Terms this shall not be interpreted as a waiver of such right or provision. 

  1. Entire Agreement

These Terms constitute the entire agreement regarding OWI, and supersede and replace any prior agreements the consortium might have regarding the OWI.