Simplicity, expressiveness, and performance

Maude's language design can be understood as an effort to simultaneously maximize three dimensions:

• Simplicity: programs should be as simple as possible and have clear meaning.
• Expressiveness: a very wide range of applications should be naturally expressible: from sequential, deterministic systems to highly concurrent nondeterministic ones; from small applications to large systems; and from concrete implementations to abstract specifications, all the way to logical frameworks, in which not just applications, but entire formalisms, other languages, and other logics can be naturally expressed.
• Performance: concrete implementations should yield system performance competive with other efficient programming languages.

Although simplicity and performance are natural allies, maximizing expressiveness is perhaps the key point in Maude's language design. Languages are after all representational devices, and their merits should be judged on the degree to which problems and applications can be represented and reasoned about generally, naturally, and easily. Of course, domain-specific languages also have an important role to play in certain application areas, and can offer a useful ``economy of representation'' for a given area. In this regard, Maude should be viewed as a high-performance metalanguage, through which many different domain-specific languages can be developed.