InteractiveDataLanguage (IDL for short, sometimes confused with the CorbaInterfaceDefinitionLanguage?)
An ArrayOrientedLanguage created by DavidStern? and commercialized by ResearchSystemsInc. Excellent for scientific data-processing. Similar to MatLab, but with earlier (and better) support for arrays > 2 dimensions. IDL was also the starting point for the PvWaveLanguage?.
Some books: