OS/2 Version 2.0 supports the execution of 16-bit applications directly, with no modification required. These applications execute as protected mode processes under operating system control, exactly as they did under previous versions of OS/2. Full memory protection and interprocess communication facilities are available to such applications.
OS/2 Version 2.0 also allows both 16-bit and 32-bit modules and resources to reside and execute within the same process. Address conversion and translation is accomplished using tiled local descriptor tables and thunks. These concepts are fully described in 16-Bit Applications in a 32-Bit Environment.