It is a commercially supported, open-source relational database management system.
Ingres was first created as a research project at the University of California, Berkeley, starting in the early 1970s and ending in the early 1980s.
The original code, like that from other projects at Berkeley, was available at minimal cost under a version of the BSD license. Since the mid-1980s, Ingres has spawned a number of commercial database applications, including Sybase, Microsoft SQL Server, NonStop SQL and a number of others. Postgres (Post Ingres), a project which started in the mid-1980s, later evolved into PostgreSQL.
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