This is the "Formal Entities eXplained/eXecuted" (FEX) Knowledge Resource.
The following license applies: https://creativecommons.org/licenses/by/4.0/deed.en
FEX is a sibling of FSL: https://github.com/softlang/fsl
FEX (Formal Entities, eXplained / eXecuted) is an emerging knowledge resource for the formal foundations of software languages. It aims to connect ontological descriptions of formal entities—such as calculi, logics, type systems, process algebras, automata, query calculi, and description logics—with executable artifacts such as interpreters, simulators, static analyses, and mechanized definitions. FEX is developed in close relation to FSL, with FSL covering the ontological aspects and FEX emphasizing executable, demonstrative, and traceable artifacts for formal entities.