BaseX vs PouchDB

BaseX is a free, open-source XML database engine and XQuery processor for data-intensive web applications. It stores XML documents, binary data, and XQuery values, and handles XML, HTML, JSON, and CSV formats. Its XQuery 4.0 processor supports the W3C Update and Full Text extensions. You can operate it from the command line, in client/server mode, or through desktop and web interfaces. The graphical interface provides a query editor with syntax highlighting, keyword search, interactive visualizations, and server administration. RESTXQ supports building web applications with XQuery, while the server offers REST and WebDAV access to databases and resources. Concurrent reads, ACID-safe write transactions, user permissions, and secure authentication are supported. BaseX runs on Linux, macOS, and Windows, with API and self-hosted deployment listed. Java 17 or higher is required, and Adoptium distributions are recommended. The BaseX plan costs nothing.

PouchDB is a free, open-source JavaScript database for storing application data locally and synchronizing it with CouchDB and compatible servers. It keeps data available offline and can sync local and remote databases after a connection returns. Its replication API can follow later changes and retry after connection failures when configured. PouchDB runs in browsers and Node.js, as well as Cordova, PhoneGap, NW.js, Electron, and Chrome apps. Browser storage defaults to IndexedDB, while Node.js defaults to LevelDB. Documents can include image or audio attachments stored as base64 data or Blobs. PouchDB includes a map/reduce API; Mango queries require the separate pouchdb-find plugin. Its asynchronous API supports callbacks, promises, and async functions, and the project names Angular, React, Ember, and Backbone as framework examples. Listed compatible servers include CouchDB 1.x, 2.x, and 3.x, Cloudant, and PouchDB Server. Replication requires a backend that speaks the CouchDB replication protocol. The project homepage says Apache PouchDB is undergoing incubation at the Apache Software Foundation.