It has been alleged that the company behind OnlyOffice is selling a modified version (P7/R7 Office) is Russia. These allegations aren't completely meritless.

For example, a commit to a third-party (?) P7-Office-plugin repo is titled "Replace OnlyOffice with R7-Office and fix encoding (UTF-8 no BOM)" (emphasis mine). (https://github.com/r7-consult/plugin-grammalecte/commit/ca45...)

The R7-Office FreeBSD port contains files named "onlyoffice-docxf.xml" and "onlyoffice-oform.xml". (https://www.freshports.org/editors/linux-r7-office/)

A GhostBSD package contains files that contain Ascensio System SIA copyright notices. (https://pkg.ghostbsd.org/stable/FreeBSD:14:amd64/latest/All/... --- Zstandard-compressed tarball)