There is also https://age.apache.org/, an extension to facilitate graph queries in postgresql.
If your org is amenable to Google Spanner or already using Spanner, it has preview support for Cypher and graph semantics: https://cloud.google.com/spanner/docs/graph/overview
Not sure if you everyone reading is aware, but Neo4j did end up turning Cypher into the openCypher spec and that allowed a lot of other graph stores to adopt Cypher as a query language.