knowledge is described as 'Knowledge is an open source information sharing service application. The application is self-hosted by Tomcat. Data can be stored in the built-in SQLite database or any PostgreSQL'. There are five alternatives to knowledge for a variety of platforms, including Mac, Windows, Linux, Online / Web-based and Self-Hosted solutions. The best alternative is Obsidian. It's not free, so if you're looking for a free alternative, you could try Raneto or Notabase. Other great apps like knowledge are HowHive (Paid) and openKB (Free, Open Source).