PostgreSQL - PostgreSQL is a powerful, open source object-relational database system.
ZeroID - ZeroNet authentication provider
SQLite - SQLite Home Page
Cesium - Explorer of Duniter communities network, to certify trusted peers, to generate an universal...
MongoDB - MongoDB (from "humongous") is a scalable, high-performance NoSQL database.
Keybase - Keybase will be a public directory of publicly auditable public keys.