IDL_GRIB files are dependent on IDL binaries. The IDL binaries on which it depends are both operating-system and microchip-hardware dependent. Building these binaries is not a trivial step, so it requires a huge commitment of resources to maintain each incremental operating-system/chipset combination. The unique AIX operating system has become too costly to maintain IDL for as its market share has diminished, and as IBM has devoted more resources to promoting its Linux systems. Unfortunately, IDL is not an open source computer language, and ITT does not provide the source code of IDL to third parties for compilation outside our building. Thus, your only options for working with the IDL_GRIB library functionality are to: a) work with them on Solaris, Linux, Mac OS X or Windows. b) work with them on IDL 6.4, the last version available for IBM AIX. Contact IDL Technical Support (techsupport@ittvis.com), if you need to or want to download IDL 6.4 for Linux (they will set you up with an FTP account). James Jones ITT Technical Support