Firebird : Firebird is a relational database offering many ANSI SQL-92 features that runs on Linux, Windows, and a variety of Unix platforms. Firebird offers excellent concurrency, high performance, and powerful language support for stored procedures and triggers. It has been used in production systems, under a variety of names since 1981.
Interbase : Borland? InterBase? raises the bar for performance and power in small footprint databases. Designed for use in situations where there is no database administrator or IT support, InterBase is powerful enough to support mission-critical applications, yet compact enough to run on very modest systems. It can be easily transported by disk, CD, or even dial-up download. And unlike enterprise databases that require expensive ecosystems of support and maintenance, InterBase requires virtually no maintenance.
Sybase : Sybase is the software integration company, delivering open standards software solutions in database, replication, business intelligence, enterprise portal, mobile, wireless, development tools, and application server technology.
DB2 : IBM's DB2 database software is full-featured, robust, scalable and easy to use. As the market share leader, DB2 provides the foundation of information on demand on Linux, UNIX and Windows platforms. DB2 UDB is specially designed and priced to meet your business needs whether large or small.
Informix : IBM Informix software is designed to optimize near-linear scalability and high availability -- while managing massive amounts of structured and unstructured data.
Berkeley DB : Berkeley DB Data Store is a high-performance, scalable, embedded data management engine that links directly into the address space of the application that uses it. There is no separate server to install or administer. The application makes a simple function call, rather than sending a message to a remote server, to store, fetch, or modify records. All the work is done in a single address space for higher performance.
Prevayler : Prevayler is the free-software Prevalence layer for Java. Queries with Prevayler are more than 9000 times faster than querying Oracle through JDBC and 3000 thimes faster than MySQL.
QED : The Quadcap Embeddable Database (QED) is High Performance pure Java database.
