The commands: "ittlicense" and "exelislicense" (which open the License Wizard application) do require an X Windows display in order to run, however there are ways to replicate the behavior that the License Wizard performs that do not require any display capabilities. The first item that is placing the license file in the correct directory with the correct name. Using the most recent release of ENVI/IDL and a default installation, that directory is located in: /Applications/exelis/license - Macintosh /usr/local/exelis/license - Linux/UNIX Once the license file is in that location, you'll want to ensure the file name is just "license.dat" so that the software will find it without having to define any additional environment variables. The next action that the License Wizard will perform is recognizing that the license manager is required to run (you can determine this by opening the license file in a plain text editor, if the line mentioning SERVER is included towards the top, that will require the license manager service to be active). To mimic these steps, again using the most recent release of ENVI/IDL as an example: 1. Open a terminal window 2. Browse to /usr/local/exelis/idl84/bin 3. First, run the command: sudo ./lmgrd_install 4. Next, run the command: ./lmgrd -c /usr/local/exelis/license/license.dat The final step should start the license manager (and allow you to open the software once done) or provide a debug log mentioning any errors encountered during the start process that can be used for troubleshooting purposes. For more information regarding previous version paths, please also see the help article below: http://www.exelisvis.com/...ked-Questions.aspx#6