IBM i

OS400 (sometimes referred to as i5/OS) is the core of the iSeries and the thing that makes it the unique system it is.

OS400 includes a very robust variation of the DB2 database.

Generally, OS400 is accessed using a 5250 emulator.

Contrary to popular belief, the OS/400 provides a large number of "Open" resources common on other systems..

• Java
• Apache Web server
• Posix compliant API's accessible from many programming languages.