Alexandria
Most note apps ask you to put each note somewhere: a folder, notebook, space, or database. Alexandria starts from a different place:
That means folders usually become tags, and repeated fields become tag properties. A Book tag might define author:string, status:select, and rating:number. A Project tag might define status:select, deadline:date, and budget:money.
The files remain yours. Alexandria stores notes under notes/ as Markdown files, keeps media under media/, and derives its search/tag index from those files.
Alexandria has one dedicated importer today: Notion, through akb-importer.
For other tools, migration is currently manual: export or convert your content to Markdown, create Alexandria notes, recreate the important tags, and fill in tag-property values as you review.
See Imports for the current importer mechanics and options.
Start with a small representative set rather than the whole archive.