Legal Notice
Last updated: 23 May 2026
> Courtesy translation. Only the French version is legally binding: Mentions légales. In the event of any discrepancy, the French text prevails.
In accordance with article 6-III of French Act no. 2004-575 of 21 June 2004 on confidence in the digital economy (LCEN), this legal notice is made available to users of the derja.fr website.
1. Site publisher
Name: Ismael Dubuc
Status: Sole trader (auto-entrepreneur / micro-enterprise)
SIREN: 939 197 554
SIRET (registered office): 939 197 554 00016
NAF code: 6201Z, Computer programming
Date established: 6 January 2025
Registered address: 30 Allée Sidney Bechet, 93430 Villetaneuse, France
Email: contact@derja.fr
> The publisher is a sole trader exempt from registration with the French Trade and Companies Register under article L123-1-1 of the French Commercial Code (IT services carried out as the principal activity).
2. Publication director
Ismael Dubuc
contact@derja.fr
3. Host
Hetzner Online GmbH
Industriestr. 25, 91710 Gunzenhausen, Germany
Phone: +49 (0)9831 505-0
Website: https://www.hetzner.com
4. Intellectual property
All content published on derja.fr (teaching vocabulary, phrases, exercises, conjugations, grammar notes, culture notes, graphic design, user interface, logo and the “Derja” trade mark, together with the application's source code) is the exclusive property of Ismael Dubuc and is protected by copyright (French Intellectual Property Code).
Any reproduction, representation, modification, adaptation, translation, extraction or reuse, in whole or in part, by any means whatsoever, without the publisher's prior written authorisation, is strictly prohibited and would constitute infringement punishable under articles L335-2 et seq. of the French Intellectual Property Code.
Only personal, non-commercial use of the service is permitted, within the scope of the subscription taken out.
5. Technical credits
The Derja application is built in React 18 and uses the following libraries and services:
| Item | Publisher / source |
|---|---|
| React and React DOM | Meta Platforms, Inc. (MIT licence) |
| @supabase/supabase-js | Supabase, Inc. (MIT licence): database and authentication |
| lucide-react | Lucide Contributors (ISC licence): icons |
| Vite | Evan You and contributors (MIT licence): build tool |
| Tailwind CSS | Tailwind Labs, Inc. (MIT licence): CSS framework |
| Fraunces, Manrope, Tajawal | Typefaces under the SIL Open Font License, self-hosted |
The libraries listed above are used under their respective open source licences. Rights in these libraries belong to their respective authors.
6. Personal data
The processing of users' personal data is described in the Privacy Policy.
7. Cookies
The use of cookies on derja.fr is set out in the Cookie Policy.
8. Terms of use and of sale
Use of the service is subject to the Terms of Use.
Subscription purchases are subject to the Terms of Sale.
9. Consumer ombudsman
In the event of a dispute not resolved with customer service, the user may refer the matter free of charge to the consumer ombudsman listed by the publisher:
CNPM: Médiation de la Consommation
27 avenue de la Libération, 42400 Saint-Chamond, France
Website: https://www.cnpm-mediation-consommation.eu
European online dispute resolution platform: https://ec.europa.eu/consumers/odr/