GDL is a free/libre/open-source incremental compiler of the IDL (tm) language. Together with its library routines it serves as a tool for data analysis and visualization. GDL is written in C++ using the ANTLR language-recognition framework. Most of the library routines are implemented as interfaces to open-source packages such as GNU Scientific Library, PLPlot, FFTW, Image.Magick, netCDF, HDF, GRIB_API, and others. Packaged versions of GDL are available for several Linux distributions and Mac OS X. As its proprietary counterparts (IDL and PV-WAVE), GDL is used particularly in geosciences and astronomy.

The talk will cover a brief description of GDL features. Presented examples will show how it can be used to access, process and visualise publicly available dataset such as weather forecast data and satellite imagery.

GDL is released under GPL. It is developed by a group of volunteers led by Marc Schellens - the project founder.