PONGO needs a command-language as a host environment and at present it can be used from two that are generally available to astronomers; the Starlink Interactive Command Language (ICL) and the IRAF Command Language (CL). You should use PONGO from which ever language is most natural (i.e. the one you or your colleagues are most familiar with). There are no significant advantages to either system, however, people intending to use IRAF/CL should note that most of this document is slanted towards ICL usage (the original “home” of PONGO) and should be prepared to consult the on-line help system, which should be more IRAF specific.
Under IRAF/CL PONGO is available as the pongo package. From ICL PONGO is available by just typing the pongo command.