What is unique about AS/400 (IBM i)?
Why is it a big deal? How is it so different from other operating systems?
Let’s look the short philosophy behind the different operation systems!
Linux: There are a lot of small devices, apps, etc. for specific tasks, and then they “link” them together to do something bigger.
Windows: Monumental target-programs (solutions) for a concrete problem. (See it mostly as a “package”).
AS/400: A stable system, with an excellent documentation and fool-proof operations. Applications are good enough alone. They are not monumental and don’t need to link them together to make something useful out of them.
The operating system itself was object-orientated already from the beginning.
What does it mean?
Everything is an object and not a file!
For example, on Linux, everything is a file, even the devices, the printers, etc.
AS400 has objects. The number of the object-types is almost 100, and the *FILE type that represents a database file of the built-in relational database is only one of them.
Few other object types:
*DTAQ: Data queue (used to queue up data entries for communicating and distributing data between different jobs).
*LIB: Library (where everything below, except directories and stream files, is stored; libraries cannot exist within other libraries)
What kind of programming languages can you use on AS/400?
Programming languages available for the AS/400 include RPG, assembly language, C, C++, Pascal, Java, EGL, Perl, Smalltalk, COBOL, SQL, BASIC, PHP, PL/I, Python and REXX. Several CASE tools are available: CA Plex (formerly AllFusion Plex), Synon, IBM Rational Business Developer Extension, Accelerator, LANSA, Uniface and GeneXus.
And there is a complete layer called PASE to help to port anything from AIX to IBM i with minimal effort.