Specialist languages for specific purposes.

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PaulFordOnMediaLanguages

Criticism

But are they low-maintainence? :

On the negative side, however, more substantial changes may become more difficult: such changes may involve altering the domain-specific language. This will require compiler technology knowledge, which not every commercial enterprise has easily available. Based on experience taken from industrial practice, we discuss the role of DSLs in software maintenance, the dangers introduced by using them, and techniques for controlling the risks involved.

Reminds me a bit of my similar criticism of DynamicIdeography, that when the tokens are complex, needs more effort and expertise to create and edit them.