The Progress 4GL is the programming language at the heart of the Progress database system.  From fairly elementary yet elegant beginnings the language has developed through 9 versions and now includes a rich panopoly of features that include GUI capabilities and object-oriented constructs.

In version 10 it was rebranded as the OpenEdge ABL (Advanced Business Language) but whatever it is called it still provides a very productive environment for developing business oriented software applications not restricted to either Windows or Unix deployment. (more details more (2) )