For developers, who are building real-time data-driven applications, Redis is the preferred, fastest, and most feature-rich cache, data structure server, and document and vector query engine.

A flexible distributed key-value database that is optimized for caching and other realtime workloads.

cachegrand - a modern data ingestion, processing and serving platform built for today's hardware

HSE: Heterogeneous-memory storage engine

Share Hash Tables With Stable Key Hints Stored In Memory Mapped Files Between Arbitrary Processes

Trie key-value database

Multipurpose C library and persistent key/value storage

Enough works to use this in production

Bun is a simple to use C++ Object Database, Object Relational Mapper (ORM) and key-value library

Embeddable Cloud-Native Key-Value Storage For Sequential Data.

Fast persistent key-value store for Nim, based on libmdbx

Fairly basic redis-like hashmap implementation on top of a epoll TCP server.

Robin Hood hash map library

A Flexible Storage Framework for HPC

A GPU-Accelerated In-Memory Key-Value Store (AWS-focused fork)

Berkeley DB 1.85 with patches and fixes applied

Key-value store based on a trie data structure to handle the keyspace.

A complete and versatile in-memory ordered key/value store for the modern RPG programming language

Key value Database using B Tree

Tiny key/value-store in a single, embeddable C file. For games, small servers, sbc, etc...