Open PL/I was designed to be, and still is, an ANSI standard PL/I compiler. Customers interested in migrating need to assume changes to existing PL/I applications may be required to remove any proprietary mainframe syntax and/or deal with differences in behavior in order to make programs portable. You should read the topic Open PL/I 8.1 for WindowsOpen PL/I 8.1 for UNIX before starting to use this feature.