Maude is a high-performance reflective language and system supporting both equational and rewriting logic specification and programming for a wide range of applications. Maude has been influenced in important ways by the OBJ3 language, which can be regarded as an equational logic sub-language. Besides supporting equational specification and programming, Maude also supports rewriting logic computation. Maude supports in a systematic and efficient way logical reflection. This makes Maude remarkably extensible and powerful, supports an extensible algebra of module composition operations, and allows many advanced meta-programming and metalanguage applications.
fmod HELLOWORLD is protecting STRING . op helloworld : -> String . eq helloworld = "Hello, world!" . endfm red helloworld .