@sirrichard@social.vivaldi.net @Vivaldi@social.vivaldi.net I only discovered it very recently. https://www.onlyoffice.com Wikipedia say it was originally developed by Ascensio System SIA (Latvian) and New Communication Technologies (Russian) in 2009 as a collaborative project TeamLab. https://en.wikipedia.org/wiki/OnlyOffice Currently a complicated set up with the ultimate holding company based in Singapore. There are, it seems both open source versions hosted on GitHub and commercial versions. It works for me & isn't Google, MS or Apple.