Confluence - Confluence is content collaboration software that changes how modern teams work
draw.io - Online diagramming application
MS SharePoint - Share, organize, and discover information with Microsoft SharePoint. Learn about SharePoint Online, OneDrive for Business, and Apps for SharePoint
LucidChart - LucidChart is the missing link in online productivity suites. LucidChart allows users to create, collaborate on, and publish attractive flowcharts and other diagrams from a web browser.
Notion - All-in-one workspace. One tool for your whole team. Write, plan, and get organized.
PlantUML - PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.