Airtable - Airtable works like a spreadsheet but gives you the power of a database to organize anything. Sign up for free.

Raneto - Open source, flat-file Knowledgebase platform that uses static Markdown files

Microsoft Teams - Microsoft Teams provides the enterprise-level security, compliance and management features you expect from Office 365, including broad support for compliance standards, and eDiscovery and legal hold for channels, chats, and files.

HowHive - Knowledgebases for teams and companies of all sizes. Knowledge sharing and finding made simple.

Creativity 365 - Cross-device content creation suite

Obsidian.md - A second brain, for you, forever. Obsidian is a powerful knowledge base that works on top of a local folder of plain text Markdown files.