"Post-gres-Q-L", "Post-grey-sequel", "Postgres"... how do you say it? And where did the name come from?
PostgreSQL was originally named POSTGRES-- all caps. The name was chosen because it was the successor to the Ingres database developed at UC Berkeley.
As the system adopted SQL standards and features, the name was changed to PostgreSQL. From the docs:
Many people continue to refer to PostgreSQL as "Postgres" (now rarely in all capital letters) because of tradition or because it is easier to pronounce. This usage is widely accepted as a nickname or alias.
Sources: