Last Verified : 2019-09-26

NOTE IDL not currently available on CORAL systems.


IDL (Interactive Data Language) is a product from Harris Geospatial Solutions. IDL is a scientific programming language used across disciplines to extract meaningful visualizations from complex numerical data. With IDL you can interpret your data, expedite discoveries, and deliver powerful applications to market. IDL is the programming language of choice for many scientists and engineers because it’s easy to learn, easy to use, and requires fewer lines of code than other programming languages, making it easier and faster to go from data to discovery.

IDL at LLNL includes four licenses for the Advanced Math and Statistics (AMS) package, two on the OCF and two on the SCF networks. Note that IDL for Mac OS X does not support AMS or ISML.


Machines and Versions

See LC visualization software page.


Links to the latest version exist in /usr/tce/bin

Multiple versions may be accessible via modules. Type module avail idl to see the available options. You can specify a particular version in the module command, e.g. module load idl/8.5

The actual installation directories are in /usr/tce/packages/idl


The module load idl command will setup your PATH and any other needed environment variables.

You can also use the environment variable IDL_PATH to include personal files in IDL's search path. For more information about using this feature, see this help article: Quick tips for customizing your IDL program search path


IDL for UNIX can be used with one of two different interfaces. Starting IDL with the idl command begins a traditional IDL session using a simple text command line interface. If you are running the X window system, IDL can also be started with the idlde command, which invokes a convenient multiple-document interface called the IDL Development Environment.

To use the Advanced Math and Statistics (AMS) routines that are available with IDL Analyst, start up IDL in the manner shown above. Calling one of the IDL AMS routines will cause an IDL Analyst license to be checked out to you until you quit IDL. LC has two licenses for AMS on the OCF and two on the SCF.

Play nice with licenses!

1) Please do not hold onto IDL licenses overnight ("hoarding") unless you are actually using them -- hoarding licenses creates artificial scarcity and encourages further hoarding by others. It's a vicious circle.

2) If you are using multiple licenses, and we run out of licenses, please consider releasing one or two so that we are not out any more.

How to get "extra" "free" licenses: An important quirk of IDL licensing is that IDL checks out only one license per node/DISPLAY, no matter how many instances of IDL you run on that node. This can be confirmed easily by running them by hand and checking the license server records. So if you get 16 CPUs on one node, each with 4 cores, you might be able to make good use of as many as 64 copies of IDL using only a single license! Please ask for more details.


At the UNIX shell prompt, you can access the help documentation by typing idlhelp

A live online version of this documentation is available on Harris Geospatial's documentation site. They also provide on-site and online training.

Help is available from the LC Hotline:, (925) 422-4531


You can install IDL on your local workstation. The software is available for Linux, Mac and Windows. The IDL Analyst and IMSL libraries are not available on OS X as of July 2012.

Only license administrators can download the IDL software from General LC users can download the installer from the CZ Confluence page. If you do not see the installer you are looking for, please contact


If you have an account on the LC platforms, you can use the LLNL LC site license to process data generated on Livermore Computing resources.

For IDL 8.6 and later

You can specify license information during installation or by running the Harris License Administrator. Please select "Use License Server" and enter the appropriate server information as seen below.

For the OCF:

  Port:  28521

For the SCF:

  Port:  28521

Offline Usage

Your desktop needs to be connected to the network to reach the license server. If you have a specific need to use your local IDL installation offline (e.g. on travel), licenses can be "borrowed" temporarily by selecting "Borrow Licenses from a Server" in the Harris License Administrator.

Again; Play nice with licenses! Please only "borrow" for offline use when absolutely necessary, and only for as long as you actually need. If you are done using a license and regain network access before the "Borrow time" expires, please "Return All Borrowed Licenses" so they are available for other users.

For older versions of IDL

IDL versions 8.5.1 and older use a different licensing system. We will be dropping support for the old licensing software in the near future; Please migrate to IDL 8.6 or later for our site license to continue to work.

To access the LC license, the LC IDL license file must be placed on your local machine. The license file can be copied from /usr/global/tools/licservers/idl/idl.lic on any LC machine where IDL is installed. If you do not have an LC account, then please contact the LC Hotline to obtain one.

Once you have download the license file to your desktop, you can tell the IDL License Wizard where the file is. The License Wizard runs during installation, or can be found in the IDL installation directory after install. In the License Wizard, follow the instructions to "install a license you have received" and navigate to your downloaded license file.