Apache Cassandra is presented as a powerful, distributed database system. Specifically, it’s described as a “partitioned row store” where data is organized into tables with a required primary key. This fundamental design positions it differently from traditional relational databases, highlighting its focus on handling large datasets across multiple nodes. The project is primarily developed in Java.

Apache CouchDB™ stands out in the database landscape with its unique blend of features centered around ease of use, reliability, and seamless synchronization. Defined by its core design principles – using JSON for documents, JavaScript for query views (MapReduce), and standard HTTP for its API – CouchDB provides a distinctive approach to data management.

This repository, hosted at https://github.com/memcached/memcached, serves as the development hub for memcached, a renowned high-performance, distributed memory object caching system. Described simply as the “memcached development tree,” this project is a fundamental utility in modern web infrastructure and distributed systems.

Diving into the source code of a major database system like MongoDB is an incredible learning opportunity for developers and engineers. This repository, officially hosted by the mongodb organization on GitHub, represents the core implementation of the popular NoSQL database.