LibreOffice is the most popular free open source office suite, you can follow their official account at:
It includes word processing, spreadsheets, presentations, diagrams etc.
It's available for Linux, Mac and Windows from the official site at https://www.libreoffice.org
There are also many LibreOffice user groups on the Fediverse:
➡️ @LibreOfficeEs (in Spanish)
➡️ @LaMouetteODF (in French)
➡️ @libreofficebr (in Portuguese)
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