Where can I download PostgreSQL?

PostgreSQL is a powerful, open source object-relational database system, a proven architecture that has earned it a strong reputation for reliability, data integrity, and correctness. xTuple is built on PostgreSQL. Learn more about PostgreSQL here: https://www.postgresql.org. 

EnterpriseDB is the worldwide provider of enterprise-class products and services based on PostgreSQL, the world's most advanced and independent open source database. To do download the EnterpriseDB installer for PostgreSQL, follow this link: https://www.enterprisedb.com/downloads/postgres-postgresql-downloads.