Open-source software is a great way to learn

1. about programming.
2. about design.
3. about debugging.

PostgreSQL is Open source ORDBMS – An international team of developers maintains PostgreSQL. Team members come and go, but the core members have been enhancing PostgreSQL’s performance and feature set since at least 1996. One advantage of PostgreSQL’s open-source nature is that talent and knowledge can be recruited as needed. The fact that this team is international ensures that PostgreSQL is a product that can be used productively in any natural language, not just English.