PostgreSQL is a feature-rich object-relational database management system, that is renowned for being one of the most stable and dependable systems available. It is cross-platform (Linux, UNIX, Windows, FreeBSD) and cross-language (PHP, Ruby, Java, Perl, Python), which makes it universal and a lot of organizations and corporations are already using it for their products or their own sites - just a couple of examples are Apple, the US Department of Labor, IMDB.com and Skype. The system is open-source and highly customizable, not mentioning that it is more advanced than other management systems in relation to handling complex operations. Also, the fact that 1 table may be up to 32 GB in size, while the database size is unlimited, makes PostgreSQL a fantastic pick for scalable apps.