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.