OS Application Model

On an OS/400 server, three application models are supported. To explain this, let's start in the middle of this chart. Traditional OS/400 applications run under the Integrated Language Environment (ILE) model. Programs in this application model use the TIMI. Above the TIMI, all programs are compiled to an intermediate form, which is automatically translated to actual hardware instructions by the kernel prior to execution. Much of OS/400 resides above the TIMI and is, thus, isolated from changes in underlying hardware. Remember, even though isolated from hardware changes, ILE applications are not interpreted. They are ‘optimized and translated’ to actual hardware instructions by the SLIC kernel.

Next, Java applications (shown on the right) use one of the following features built into the SLIC kernel: either the JVM, Just-In-Time (JIT) compiler, or Java translator. The Java support built into OS/400 delivers one of the highest-performing and most reliable Java machines in the industry.