Junlei Li is a programmer from Tianjin, China, with 10 years of experience in software design and programming. Junlei Li began programming under i5/OS (formerly known as AS/400, iSeries) in late 2005. He is familiar with most programming languages available on i5/OS—from special-purpose languages such as OPM/ILE RPG to CL to general-purpose languages such as C, C++, Java; from strong-typed languages to script languages such as QShell and REXX. One of his favorite programming languages on i5/OS is machine interface (MI) instructions, through which one can discover some of the internal behaviors of i5/OS and some of the highlights of i5/OS in terms of operating system design.