Apache OpenOffice - Apache OpenOffice is an open source, office document productivity suite.
Confluence - Confluence is content collaboration software that changes how modern teams work
LibreOffice - Free office suite, open source, and compatible with .doc, .docx, .xls, .xlsx, .ppt, .pptx files. Updated regularly – download for free. Originally based on OpenOffice.org.
MS SharePoint - Share, organize, and discover information with Microsoft SharePoint. Learn about SharePoint Online, OneDrive for Business, and Apps for SharePoint
Microsoft 365 - Boost your productivity with reliable access anywhere with services like email, calendar, file sharing, meetings, instant messaging, and Office Online
Sharepoint Online - SharePoint is a secure place to store, organize, share, and access information from almost any device.