A free and open-source office suite. It uses the international standard OpenDocument file format (ODF) as it's native format to save documents. It also supports the file formats of most other major office suites (including Microsoft Office).
A free and open-source office suitedeveloped by Ascensio System SIA. The desktop edition is an offline version of OnlyOffice editing suite and supports collaborative editing features (when connected to the portal, Nextcloud, or ownCloud).