According to ONLYOFFICE, “[we have] spent years building a fully functional, production-ready online document editor”. It claims Euro-Office “uses technology derived from ONLYOFFICE editors” in violation of the GNU Affero General Public License v3 (AGPL v3) under which the code is distributed.
“The “Euro-Office” initiative represents an evident and material violation of ONLYOFFICE licensing terms and of established principles of international intellectual property law. We require full and immediate compliance with all applicable licensing conditions, including — but not limited to — the preservation of ONLYOFFICE branding, logo, and all required attribution elements as defined in our licensing terms.”
You might wonder why the Nextcloud team didn’t just collaborate with ONLYOFFICE instead of forking its code. They cited a “number of reasons,” including that ONLYOFFICE is a Russian company that tends to obscure its origins. Developers often leave code comments in Russian, and many users are hesitant to use software potentially linked to the Russian government. They also claimed that ONLYOFFICE discourages contributions, ignores pull requests, and lacks transparency, since commit messages frequently reference internal issue trackers only.
ONLYOFFICE has previously been criticized by its open-source competitor, LibreOffice, for being “fake open source.” This is partly because ONLYOFFICE defaults to OOXML formats like DOCX, XLSX, and PPTX, rather than promoting open standards like OpenDocument Format (ODF), a practice LibreOffice says helps maintain Redmond’s monopoly and lock in users.
Requiring preservation of specified reasonable legal notices or author attributions in that material or in the Appropriate Legal Notices displayed by works containing it
A logo isn’t attribution, and even if it was there’s no way it could be considered reasonable to require it if they don’t allow you to use it.
They seem to have a questionable interpretation of the AGPL https://isitreallyfoss.com/projects/onlyoffice/
Considering the specific clause they cite allows
A logo isn’t attribution, and even if it was there’s no way it could be considered reasonable to require it if they don’t allow you to use it.