MySQL - The world's most popular open source database
Auth0 - Auth0 is a program for people to get authentication and authorization services for their own business use.
PostgreSQL - PostgreSQL is a powerful, open source object-relational database system.
Spring Security - The Spring portfolio has many projects, including Spring Framework, Spring IO Platform, Spring Cloud, Spring Boot, Spring Data, Spring Security...
SQLite - SQLite Home Page
Amazon Cognito - Amazon Cognito lets you add user sign-up, sign-in, and access control to your web and mobile apps quickly and easily. It scales to millions of users and supports sign-in with social identity providers and enterprise identity providers via SAML 2.0.