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Why is Trilium so unknown?
(github.com)
If it's free and open source and it's also software, it can be discussed here. Subcommunity of Technology.
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For whatever it's worth, this is the first I've ever heard of it (I thought you were referring to the IM client at first). It doesn't seem to be on any of the popular self-hosted software lists (like https://github.com/awesome-selfhosted/awesome-selfhosted).