Okay, you guys are close. The AS400 (or now known as the iSeries eServer) is a midrange level computer designed for businesses and their applications. Here is a link to IBM's website
The system is an extremely stable computer which is one big database. The files that store data would be called a table in a database. RPG is the most common language, however you can do COBOL, C, C++, Java, Perl, and possibly more. It can be your all in one solution for a server. It uses Apache and Tomcat for the web, it has it's own file server for Windows, and of course it is your database and application server. And all this can be run at the same time on one system!
Like the linux community, the AS400 is a tight group and are usually very passionate about the platform.
I can go on and on if you wanted, but I think this would be a good intro. If your are interested in asking many more questions, there is a mailing list dedicated to the AS400 or iSeries. Head over to
and sign up for the MIDRANGE-L list.
I am glad to see that you are interested. If you have any more questions, just ask! Mike Wills
AS400 Programmer