When I was in Deltech I had to use the AS/400 operating system by IBM. Now I’ve used Linux, Unix, Mac, and Windows, and I have to say that the AS/400 is more like a Unix operating system than the Mac, which was actually built on top of Unix. The difference between the AS/400 and other operating systems? AS/400 wasn’t built by people who had worked with Unix systems. Also while 32 bit operating systems are still relevant, and only came to be popular 2 to 3 years ago, the AS/400 has been on a 64 processor since the mid 90’s. Now personally I have worked on an IBM AS/400 iSeries that we used to run reports in class. Eventually we got to see how it handled C++ programs and SQL commands. It handled it better than most Windows machines.