Application of extensible languages to specialized application languages

It is becoming increasingly clear that one of the major thrusts of the programming language field is in the direction of specialized application languages - sometimes called special purpose languages. These specialized application languages have already been developed for such diverse fields as civil engineering, electrical engineering, computer assisted instruction, systems programming, equipment checkout, movie animation, etc. Of the roughly 165 languages currently in use in the United States, approximately 85 of them might be classified as specialized. (See the list in Reference 1.) For description and illustration of many of these, see Chapter 9 in Reference 2. All languages are applications oriented. In fact, this is probably the best way to categorize the set of programming languages. However, some application areas are obviously larger than others, e.g., scientific computation (numeric and non-numeric) and business data processing. The main concern here is with the more specialized languages. While each person may have a different idea of what the categories of specialization should be, there can be little dispute about the wide diversity and large number of them.