Installation and portability issues
Is it possible to run GDL on MS-Windows?
Solution 1: It's possible to compile GDL under Cygwin or e.g. to run GDL under the coLinux platform.
Solution 2: since GDL 0.9.3, GDL should be compilable under MS-windows thanks to Jeong Bin Park Please follow the instructions described here. Feedback realy welcome. Please notice SPAWN functionnalities currently not working, which explain large number of FAIL in testsuite.
N.B.: Due to lack of Windows developer- or user-base there is virtually no testing done on Windows, though. Help welcome!
Compatibility with IDL
Is there an equivalent of IDL Virtual Machine in GDL?
No. GDL is free/libre/open-source software. The distinction between a developers' (costly) version and a users' (free) version is not applicable. Any user is free to use the full power of GDL.
Is there a way to save/distribute pre-compiled GDL routines (as .sav files in IDL)?
No. GDL does not support saving/loading pre-compiled routines yet. It does support saving/loading variables into IDL-compatible .sav files, though. Since compatibility with IDL-saved routines is not going to be possible anyhow, and since the virtual-machine context is not applicable to GDL (see above), implementing routine saving has a low priority.
Does GDL support the so-called ''object graphics'', ''function graphics''/''new graphics''?
No. GDL supports ''direct graphics'' only.
Why does the CATCH statement not work properly in GDL?
It was one of very few IDL syntax elements not implemented in GDL till version 0.9.3. Since 0.9.3 it should work as expected. Please update GDL if using an older version.
Why the continent/country/shoreline boundaries have so poor resolution in comparison with IDL
Try the HIRES keyword to MAP_CONTINENTS!