Freestyle Markup Language: Spezifikation einer polyhierarchischen Auszeichnungssprache

This paper provides a new generation of a markup language by introducing the Freestyle Markup Language (FML). Demands placed on the language are elaborated, a grammatical definition and a corresponding object graph are presented and a reference implementation is introduced. The result of this paper is a complete specification of FML. Today, the Extensible Markup Language (XML) is broadly accepted as a standardized serialization format and universal transfer syntax. XML allows the markup of content according to the well-formedness constraints ('properly nested') only in strict mono-hierarchical structures markup in non-hierarchical or multi-hierarchical structures is not inherently provided in the language: This deficit is sufficiently commented and represents a problem for many application scenarios. Moreover, further restrictions exist that complicate an unlimited use of XML in practice and prohibit an intuitive 'freestyle' markup. The fact that markup languages are not only used in the original sense in the typographic field but mostly and increasingly for any data structures confirms the necessity to further develop present markup standards, in analogy to the evolution of data structures from lists via table relations and trees up to graphs. The descriptive markup language FML consolidates deficit discourses, discussions as well as solution approaches and will offer a 'freestyle markup' beyond purely hierarchical structures.