Some links are provided below for posterity.
Migration: If you've been using Athens, you can try to export your data using https://github.com/bshepherdson/athens-export, which converts your pages to markdown and a logseq-compatible directory. This seems to have worked for my personal graph, but it is not an officially supported project, so your mileage may vary.
Athens helps teams capture and synthesize knowledge together. Built on a graph database, Athens helps map and communicate complex knowledge in complex domains.
You can demo Athens in your browser (no changes are saved)
You can download the free and OSS desktop app
Documentation (not guaranteed to be up to date)
Thank you to the Sponsors and Contributors who supported us along the way. Thank you.