SurrealDB

vs

PouchDB

Supabase is a free and open-source self-hosted and SaaS provided alternative to Firebase. With Supabase you can add a realtime REST API to a PostgreSQL without writing a single line of code.

Fauna is the data API for client-serverless applications. It provides web-native GraphQL interface, with support for custom business logic and integration with the serverless ecosystem. Fauna transforms the traditional DBMS into a Data API that gives you all of the capabilities of traditional database, without sacrificing flexibility, scale, and performance. By utilizing a globally-distributed storage and compute fabric, Fauna-powered applications are delivered to end-users fast and reliably on modern security infrastructure.

EdgeDB is a database designed on top of Postgres with the goal of eliminating some of the shortcommings of relation and NoSQL databases.  At first glance, EdgeDB looks like a regular object relational mapper (ORM), however it's far more than that, It's a full-fledged database with a formally-defined query language, a migrations system, a suite of client libraries in different languages, a command line tool, and a soon comming cloud hosting platform. The goal of EdgeDB has been to rethink every aspect of how developers model, migrate, manage, and query their database.

CouchDB is a free and open-source document-oriented NoSQL database developed by the Apache Foundation. The database is written and implemented in the language Erlang and provides the use of multiple formats and protocols to store, transfer, and process data. With CouchDB you query data with JavaScript using MapReduce, and HTTP for an API. Which can be done across multiple distributed CouchDB instances as the database has the ability to synchronize multiple copies of the same database, across servers.

MongoDB is an open-source document-oriented distributed database built for modern applications. MongoDB uses JSON-like documents with optional schemas and is classified as a NoSQL database. The database is freely distributed under the Server Side Public License, but MongoDB provides commercial version of the database for enterprise-scale applications.

ArangoDB is a database system that was designed to support key/value, document, and graph data to be stored together, and queried via a unified language called AQL. The project is developed by ArangoDB GmbH, and released free and open-source under the Apache License 2.0. The universal "native multi-level" design of the database allows for a flexible approach when structuring and building an application, a feature that many have come to love.