MongoDB is a document database with the scalability and flexibility that you want with the querying and indexing that you need
Cost / License
- Freemium
- Source Available (SSPL-1.0)
Application type
Platforms
- Mac
- Windows
- Linux
- Online
- BSD
Apps similar to XAP include MongoDB, which has a free version. Other options are Redis, CouchDB, DiceDB and Apache Cassandra. There's no shortage of In-memory Databases like XAP, with more than 25 alternatives for Linux, Windows, Mac, self-hosting and the web.
MongoDB is a document database with the scalability and flexibility that you want with the querying and indexing that you need
The in-memory data store used by millions of developers as a cache, vector database, document database, streaming engine, and message broker.

Apache CouchDB is a distributed, fault-tolerant and schema-free document-oriented database accessible via a RESTful HTTP / JSON API. It includes incremental map / reduce mechanics for queries and keeps data safe with an append-only datastore.

DiceDB is an open-source, fast, reactive, in-memory database optimized for modern hardware. Commonly used as a cache, it offers a familiar interface while enabling real-time data updates through query subscriptions.

The Apache Cassandra database is the right choice when you need scalability and high availability without compromising performance.

Valkey is an open source (BSD) high-performance key/value datastore that supports a variety of workloads such as caching, message queues, and can act as a primary database. Valkey can run as either a standalone daemon or in a cluster, with options for replication and high...
Intent Bus is a lightweight, distributed job coordinator designed for developers who want reliable task execution without managing broker infrastructure.


Azure Cosmos DB is a NoSQL document database service designed from the ground up to natively support JSON and JavaScript directly inside the database engine. It’s the right solution for web and mobile applications when predictable throughput, low latency, and flexible query are...

Cockroach is a distributed key/value datastore which supports ACID transactional semantics and versioned values as first-class features. The primary design goal is global consistency and survivability, hence the name.

Bigtable is a fully managed wide-column and key-value NoSQL database service for large analytical and operational workloads as part of the Google Cloud Platform portfolio.
HyperDex is the next generation key-value store. It provides a rich API, strong consistency, fault-tolerance, and transactions.