There are lots of useful open source note-taking tools out there. Standard Notes and Trilium are designed with your data as the top priority.

Open-source software communities and projects provide developers with opportunities to collaborate, contribute, and learn from a diverse range of projects across various domains. From exploring source code repositories to participating in community discussions and events, developers can gain hands-on experience and expand their skills while contributing to the advancement of open-source software. Additionally, engaging with open-source projects fosters collaboration, knowledge sharing, and innovation within the global developer community, driving the evolution of technology and fostering a culture of transparency and collaboration.

Open Source Way

A popular application that isn't open source is Notion, but here are two options that respect your privacy. Standard Notes uses an intuitive and natural tagging system to help you organize your content.

My favorite open source alternatives to Notion

This are not alternatives to Notion. “Open source notes apps” is the right title

I moved my content off Notion and on to a personal instance of Outline, which I think satisfies the title, it is an alternative to Notion. <a href="https://github.com/outline/outline" target="_blank" rel="noopener nofollow">https://github.com/outline/outline</a>

Unfortunately, he did not talk about alternatives to Notion. He just presents his own setup.
I’m missing Obsidian or Joplin which are real alternatives to Notion.