Why Gellish

  • Gellish is a standard language, methodology and tools for expressing information and storing such expressions in databases and semantic networks in a computer interpretable and system independent way. It enables
    – data exchange between systems
    – data integration of data among systems of multiple parties without the burden of data conversions.
    Gellish consists of:

    • A family of formalized natural languages, including Formalized English, Formalized Dutch and other formalized natural language variants. The language definition has the form of a computer interpretable taxonomic dictionary and ontology and a simple syntax. Gellish is a subset of a natural language and enables expressing and interpreting information in a system independent way.
    • A consistent methodology for semantic modeling of information.
    • Reusable software tools that support system independent data exchange between application systems of various parties as demonstrated by a reference application on GitHub.

The objectives of the methodology, language and tools are:

  • To enable interoperability of systems and information integration, through
    • System independent information models.
    • A standardized formalized natural language for expressing information, knowledge, requirements as well as queries and responses.
    • A universal data exchange format, supported by software tools.
    • Enabling synonyms, homonyms, proprietary terminology and automated translation.
  • To enable applying logic reasoning on data, knowledge and requirements, for
    • Intelligent searching,
    • Computer augmented design, fabrication and maintenance,
    • Computer augmented verification of deliverables versus requirements and knowledge.
  • To enable simplifying implementations of system interfaces and generalizing user interfaces.

For further information see:

  • The wiki guide about expressing information, queries and dialogs in one of the formalized natural languages and the exchange and interpretation of messages in such a formal language. This includes data as well as queries and responses. The guide applies the Gellish Semantic Modeling Methodology.
  • The Gellish Formalized English language definition base and the Gellish Syntax and various application examples are free of charge available via the download area.
    The language definition consists of a taxonomic dictionary-ontology. It includes computer interpretable definitions of concepts, a vocabulary and relations between the concepts. The source data is a collection of tables that themselves complies with the definition of the Gellish syntax. This makes that it can be imported in any application system that can read Gellish expressions. Thus it provide the application software with a basis for expressing information and queries in the formalized languages and for interpreting, searching and the application of logic reasoning.
  • The free open source Gellish Communicator software. The software is the result of a development project on GitHub. It is a reference application that demonstrates how Gellish can be implemented and used. The software includes an object oriented Gellish database, with various usage examples, data verification, searching in data and documents and a generic user interface.

Other documentation:

  1. The Semantic Modeling Methodology

    A consistent high quality expression of information requires the application of a solid methodology. The Gellish methodology is described in the book ‘Semantic Information Modeling Methodology‘. It describes a systematic approach for expressing information, knowledge about possibilities, requirements in explicit contexts and definitions, while using a Gellish formalized language. The book is illustrated with many practical examples.

  2. The Gellish language for Semantic Modeling

    The Gellish formalized languages, and Formalized English in particular, is described in the book ‘Semantic Information Modeling in Formalized Languages‘. It explains how the formalized languages of the Gellish family are defined and how that enables universal information exchange and interoperability of systems. It also explains how the language can be extended, for example with your own concepts and terminology. The book is an explanation of the content of the Gellish Taxonomic Dictionary-Ontology. The book is also available as eBook.

  3. Formalized Natural Languages – PhD

    The book ‘Formalized Natural Languages‘, Definition and Application of Universal Information Modeling Languages’ (2014). This is the 2nd edition of ‘Gellish, a Generic Extensible Ontological Language’ (2005); PhD, Delft University of Technology. It describes the background of the Gellish family of formalized natural languages and Formalized English in particular.

  4. Taxonomic Dictionary of Relations

    The book ‘Taxonomic Dictionary of Relations’ is a printed version of the definitions of kinds of relations and their denoting phrases and inverse phrases that form the core of the definition of the Gellish family of formalized languages. The kinds of relations are also suitable to be used as standard kinds of relations (predicates, properties) in RDF/OWL based data exchange (the book is also available in Dutch). The section of the dictionary called ‘Formal language definition base’ is a computer interpretable ontology that is an extended version of the book’s content. The Taxonomic dictionary of relations is also described at the dictionary page of this website.


  • Information Management and Information Maturity Assessment Guide

Benefits of formalized languages

A break-through for interoperability

Formalized languages, such as Formalized English and Formalized Dutch (Geformaliseerd Nederlands) are a form of standardized computer interpretable subsets of natural languages. Their definition includes a formal syntax (expression format) and an electronic Taxonomic Dictionary-Ontology. They enable expressing information, knowledge and requirements in a human and computer interpretable way that is ‘neutral’ and system independent. A formalized language has an unlimited scope, in contrast to most conventional data models (databases) that have a fixed and limited scope. Gellish formalized languages are standardized formal subsets of natural languages. Their native syntax enable presentations in a tabular form, suitable for databases and data exchange messages. Other formats are also possible, such as RDF/XML. Gellish is compliant with ISO 16354.

Application of a formalized language, such as Formalized English, enables real interoperability or integration of data from different sources. It also enables integration of data, documents, and 2D drawings and 3D models. The language is generally applicable and is extensible. Its main application area’s are: the creation of compatible and consistent databases such as for system independent Product and Process Models, Facility Information Models (FIMs), Building Information Models (BIMs), product catalogs as well as knowledge and requirements, including business rules. Furthermore, it enables smooth data exchange between systems and business parties and eliminating costly data conversions in case of data migration and data integration. It is also applicable for development and application of electronic Dictionaries, Taxonomies, Thesauri and Ontologies.

The definition of Gellish Formalized English, including the taxonomic dictionary-ontology is available free of charge via the download area. Gellish can be used and implemented in various ways, including as object oriented database (as demonstrated in the Communicator reference application on GitHub), in conventional SQL database systems, or in XML, or in RDF, OWL or in simple JSON or CSV files or as spreadsheet tables. Gellish formalized languages are ’embedded languages’, which means that they do not need a meta-language for their definition or interpretation.

Formalized Language variants

Each natural language is intended to have its Gellish formalized language variant, whereas the various formalized languages share the same concepts. Formalized English and Formalized Dutch (Gellish Geformaliseerd Nederlands) are examples of such language variants from the Gellish family of formalized languages. Each concept in any of the formal languages in the family is represented by a unique identifier (a Gellish UID) which is an arbitrary language independent string that denotes a whole number, or it may be a (public or private) code that is preceded by a prefix followed by the seperator colon (:). The default reserved prefix is GEL.
Translations of terms and phrases in various languages share the same UIDs. Thus different Gellish variants share the same concepts and kinds of relations, because their UIDs are identical although their terminology is different. This enables automated translation of Gellish expressions and models between natural languages for which formal dictionaries are available.
For example, Gellish formal domain dictionaries are available for Waste Water Terminology in English, French, German and Dutch conform the terms in ISO 16323, but they all share the same UIDs.

Free available downloads:

  • The Formalized English Dictionary is free of charge downloadable.
  • The Gellish Syntax and Contextual Facts document includes a definition of the Gellish Expression Format as well as the definition of the Gellish Contextual Facts. See also an accompanying XML Schema of an earlier version.
  • The GitHub project on the Gellish Communicator reference application software provides some additional Gellish files in the dictionary and data directories.
  • An example of a Semantic Information Model of a road network, available in Gellish Formal English as well as in Formal Dutch (Formeel Nederlands).
  • An example of information about electric cables, including also catalogue data from various suppliers.