PostgreSQL is described as 'Powerful, open source object-relational database system with over 35 years of active development that has earned it a strong reputation for reliability, feature robustness, and performance' and is a very popular relational database in the development category. There are more than 50 alternatives to PostgreSQL for a variety of platforms, including Windows, Linux, Mac, Self-Hosted and Web-based apps. The best PostgreSQL alternative is SQLite, which is both free and Open Source. Other great apps like PostgreSQL are MySQL Community Edition, MariaDB, MongoDB and Microsoft SQL Server.