Heterogeneous visual languages-integrating visual and textual programming

After more than a decade of research, visual languages have still not become everyday programming tools. In the short term, an integration of visual languages with well-established (textual) programming languages may be more likely to meet the actual requirements of practical software development than the highly ambitious goal of creating purely visual languages. In such an integration, each paradigm can support the other where it is superior. Particularly attractive is the use of visual expressions for the description of domain-specific data structures in combination with textual notations for abstract control structures. In addition to a basic framework for heterogeneous languages, we outline the design of a development system that allows rapid prototyping of implementations of heterogeneous languages. Examples are presented from the domains of logical, functional and procedural languages.