Language support for model-driven software development

This paper is about language technology for facilitating model-driven software development. We argue that two features are important for this purpose: (a) support for explicit meta-representation of programs as an AST-like structure (AST stands for abstract syntax tree) accessible in a programmatic way before and beyond the compilation, and (b) support for user-defined annotations of program elements. That is, we argue for language platforms organized around a Generalized Annotated AST, or GAAST languages for short. We outline the problems with a model-driven development process based on languages without such a support and show how GAAST language technology addresses these problems.