Although the license allowed proprietary products based on Postgres, the code did not develop in the proprietary space at first — somewhat surprisingly considering the advantages Postgres offered. The main offshoot originated when Paula Hawthorn (an original Ingres team member who moved from Ingres) and Michael Stonebraker formed Illustra Information Technologies to make a proprietary product based on Postgres.
In 2000, former Red Hat investors created the company Great Bridge to make a proprietary product based on PostgreSQL and compete against proprietary database vendors. Great Bridge sponsored several PostgreSQL developers and donated many resources back to the community, but by late 2001 closed due to tough competition from companies like Red Hat and to poor market conditions.
In 2001, Command Prompt, Inc. released Mammoth PostgreSQL, a proprietary product based on PostgreSQL. In 2008, Command Prompt, Inc. released the source under the original license. Command Prompt, Inc. continues to support the PostgreSQL community actively through developer sponsorships and projects including PL/Perl, PL/php, and hosting of community projects such as the PostgreSQL Build Farm.
In January 2005, PostgreSQL received backing by database vendor Pervasive Software, known for its Btrieve product which was ubiquitous on the Novell NetWare platform. Pervasive announced commercial support and community participation and achieved some success. In July 2006, Pervasive left the PostgreSQL support market.
In mid-2005 two other companies announced plans to make proprietary products based on PostgreSQL with focus on separate niche markets. EnterpriseDB added functionality to allow applications written to work with Oracle to be more readily run with PostgreSQL. Greenplum contributed enhancements directed at data warehouse and business intelligence applications, including the BizGres project.
In October 2005, John Loiacono, executive vice president of software at Sun Microsystems, commented: "We're not going to OEM Microsoft but we are looking at PostgreSQL right now," although no specifics were released at that time. By November 2005, Sun had announced support for PostgreSQL. By June 2006, Sun Solaris 10 (6/06 release) shipped with PostgreSQL.
In August 2007, EnterpriseDB announced the Postgres Resource Center  and EnterpriseDB Postgres, designed as a fully configured distribution of PostgreSQL including many contrib modules and add-on components. EnterpriseDB Postgres was renamed to Postgres Plus in March 2008. Postgres Plus is available in two versions: Postgres Plus Standard Server which has all the features of PostgreSQL plus additional QA testing, integrated components, tuning and one-click install, and Postgres Plus Advanced Server which has all the features of Postgres Standard Server plus Oracle compatibility, scalability features, and DBA and developer tools. Both versions are available for free and are fully supported, though the free version of Postgres Plus Advanced Server is restricted by a "limited use" license, which is defined as "confined to a single CPU, utilizing 1 GB RAM, storing no more than 6GB of data in a NON-PRODUCTION environment."
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