How many PostgreSQL users are there, worldwide?
Our wide distribution through the open source world and liberal licensing make that a difficult question to answer with any accuracy. A previous version, 8.0, had an estimated one million downloads within a seven months of release. However, most users get PostgreSQL with a Linux distribution, or with some of the many other products, OSS software, and hardware devices that include PostgreSQL. SDMagazine in a survey in summer 2004 estimated us as the 5th most popular SQL database system in the US for new projects, we are the most popular database download on Freshmeat, and many people have called us the most popular major database system in Japan. We have approximately 30,000 people on our community mailing lists, but of course many users do not subscribe to a list.