PostgreSQL - Advanced open source database
"PostgreSQL is a powerful, open source relational database system. It has more than 15 years of active development and a proven architecture that has earned it a strong reputation for reliability, data integrity, and correctness. It runs on all major operating systems, including Linux, UNIX (AIX, BSD, HP-UX, SGI IRIX, Mac OS X, Solaris, Tru64), and Windows."
"Not only is MySQL the world's most popular open source database, it's also become the database of choice for a new generation of applications built on the LAMP stack (Linux, Apache, MySQL, PHP / Perl / Python.) MySQL runs on more than 20 platforms including Linux, Windows, OS/X, HP-UX, AIX, Netware, giving you the kind of flexibility that puts you in control."
Sybase ASE Express Edition for Linux
"First enterprise-class commercial database that can take you from pilot to deployment for zero dollars and zero risk. You can develop a pilot project on Linux without cost or risk AND without scrimping on performance or manageability. Since it's an industrial-strength data management platform, you'll be able to handle growth and evolving requirements without painful, expensive upgrades"
