Editing Object REXX (section)

=== Cross-platform interoperability ===
ooRexx is designed to retain [[Rexx#Features|all the features of classic Rexx]] and essentially complies with the ANSI standard for the Rexx language (X3.274-1996, "Programming Language REXX").<ref name=":0" /> In contrast to an optional specification in the ANSI standard, ooRexx does not allow characters such as <code>@</code>, <code>#</code>, <code>$</code> and <code>¢</code> in symbols. While in classic Rexx the expression <code>b. = a.</code> results in <code>b.</code> being assigned the default value of <code>a.</code>, the interpreter makes <code>b.</code> an alias for <code>a.</code>. In addition, ooRexx allows <code>--</code> as a comment mark and <code>-</code> as a line continuum, which are not specified in the standard.<ref name=":0" /> 

Classic Rexx scripts usually run without changes under ooRexx, making it easy to migrate to OOP features at the desired rate while preserving the time invested in the original code.<ref name="fosdick" /> As the interpreter supports a large number of platforms, code migration to these is also feasible.