You hit the nail on the head. Canvos does not hide the fact that they assemble their platform using a stack of pre-existing, hardened open-source tools.

Euro-Office Docs is a direct open-source fork of ONLYOFFICE (specifically its AGPL-licensed codebase).

A collective of European companies and open-source platforms—including Nextcloud, IONOS, OpenProject, and XWiki—joined forces to fork ONLYOFFICE and create Euro-Office. They did this for a few highly specific reasons:

1. True European Governance: The upstream ONLYOFFICE project is managed by a company with historical roots and development teams tied to Russia (and registered in Latvia). For European governments and high-security enterprises seeking “absolute digital sovereignty,” this created compliance and geopolitical friction. Euro-Office shifts governance entirely to a European consortium.
2. Cleaning up “Black Boxes”: The creators of Euro-Office noted that upstream ONLYOFFICE contained outdated build instructions, messy commit logs, un-vetted binary blobs, and code comments written in Russian. The Euro-Office fork aims to thoroughly audit, clean, and make the codebase transparent.
3. Preventing Feature Paywalls: ONLYOFFICE has historically frustrated the open-source community by occasionally taking features that used to be free (like mobile document editing or the administrator control panel) and moving them behind commercial enterprise paywalls.

By integrating Euro-Office Docs, Canvos gets a highly mature, browser-based office suite with excellent Microsoft Office (.docx, .xlsx, .pptx) compatibility out of the box, while ensuring the code is fully transparent and legally secure under EU standards.