Athens Research

Athens Research is an open-source, local-first knowledge graph for research and notetaking. It features block-based pages, bidirectional linking, and a graph overview. Data is stored locally in an EDN file (Clojure data format). It's a community-driven alternative to Roam Research, emphasizing transparency and data ownership.

It's free to use and self-host. It ranks as a credible open-source option for networked thought, though its development pace has slowed compared to some competitors.