Reference index / maintained

Classic XML and programming references.

Focused explanations of XML technologies, schema architecture, transformations, semantic models and structured-data examples.

References35

FormatHTML

01 / REF

XSLT Through Practical HTML Templates

Learn XSLT by treating a stylesheet as a declarative template that matches XML nodes and produces HTML, XML, text or JSON output.

→02 / REF

Zero, One or Many XML Schema Namespaces

Choose a namespace strategy for XML vocabularies and understand no-namespace schemas, target namespaces, imports and compound documents.

→03 / REF

XProc Pipelines for XML Processing

Understand XProc pipelines, steps, ports and options for repeatable XML validation, transformation and document-processing workflows.

→04 / REF

Microformats and Structured HTML

Understand how microformats add machine-readable people, events and relationships to ordinary HTML through established class conventions.

→05 / REF

XML Schema 1.1 Features and Processor Support

Review XSD 1.1 assertions, type alternatives, open content and compatibility considerations before adopting XML Schema 1.1.

→06 / REF

Extending XML Schemas Safely

Design XML Schema extension points with type derivation, substitution groups, wildcards and version-aware consumer policies.

→07 / REF

XSLT and XPath Tutorial

Learn the relationship between XPath selection and XSLT template rules for transforming XML into HTML, XML, text and JSON.

→08 / REF

Why Use OWL for Ontologies?

Understand when OWL adds formal classes, properties and inference beyond XML syntax, schemas and simple controlled vocabularies.

→09 / REF

NVDL for Compound XML Documents

Use Namespace-based Validation Dispatching Language concepts to route parts of compound XML documents to the appropriate schemas.

→10 / REF

Hide or Expose XML Namespaces

Decide when XML instance documents should expose vocabulary namespaces and how qualification affects composition, XPath and consumers.

→11 / REF

Extensible XML Content Models

Design extensible XML content models with governed wildcards, versioned namespaces and consumers that handle unknown content safely.

→12 / REF

Variable Content Containers in XSD

Model XML containers whose permitted child content varies by context using choices, substitution groups, wildcards and explicit profiles.

→13 / REF

ISBN XML Schema Example

Use an ISBN-13 XML Schema example and understand the boundary between lexical XSD patterns and checksum validation rules.

→14 / REF

XML Schema and Transformation Tutorials

Follow structured tutorials for XML Schema, Schematron, XSLT, XProc, namespaces, extensibility and data-contract interoperability.

→15 / REF

Currency Codes in XML Schema

Model currency identifiers and monetary amounts in XML without freezing an external code list into an unmaintainable schema release.

→16 / REF

DFDL: Describing Binary and Text Data Formats

Learn how Data Format Description Language maps existing text and binary formats to XML, and how it differs from parser generators such as ANTLR.

→17 / REF

Functional Programming for Data Transformations

Apply immutability, composition, recursion and higher-order functions to XML, JSON and general data transformations without adopting an all-or-nothing style.

→18 / REF

Formal Languages, Grammars and Parsers

Connect regular and context-free grammars with finite automata, pushdown automata, parsing strategies and practical data-format design.

→19 / REF

OWL Ontology Engineering Guide

Model classes, properties and logical axioms with the Web Ontology Language, then test the intended and unintended inferences produced by a reasoner.

→20 / REF

RDF Graph Data Fundamentals

Understand RDF triples, IRIs, blank nodes, literals, named graphs and serialization choices without confusing the graph model with one concrete syntax.

→21 / REF

RDF Schema Classes and Properties

Use RDF Schema to publish class and property vocabularies, and understand entailments from subclass, subproperty, domain and range statements.

→22 / REF

h-card: People and Organizations in HTML

Publish contact and identity information in ordinary HTML with the modern h-card vocabulary, clear canonical URLs and testable value parsing.

→23 / REF

h-event: Events and Dates in HTML

Mark up public events with h-event, unambiguous dates, stable URLs, locations and timezone-aware machine-readable values.

→24 / REF

h-review: Reviews in Human-Readable HTML

Structure a visible review with h-review while preserving authorship, rating scale, subject identity and editorial transparency.

→25 / REF

h-resume: Résumés and Experience in HTML

Represent a public résumé with h-resume, an h-card identity, dated experience and education entries, skills and privacy-aware publishing choices.

→26 / REF

AHAH and Progressive HTML Fragment Updates

Understand the historical AHAH pattern—Asynchronous HTML and HTTP—and apply its durable lessons to modern server-rendered fragment updates.

→27 / REF

Why Microformats Put Data in HTML

Understand the design purpose of microformats: reuse visible HTML, adopt small conventions and let useful structure evolve from real publishing practices.

→28 / REF

Grammar Schemas and Rule-Based Schemas

Understand why grammar-based languages such as XSD and rule-based Schematron answer different validation questions and work best as complementary layers.

→29 / REF

Schematron Usage, Phases and Diagnostics

Use patterns, rules, assertions, reports, phases and diagnostics to turn contextual XML requirements into maintainable validation profiles.

→30 / REF

Schematron Processing and Report Flow

Follow a Schematron schema from patterns and XPath contexts through validation to structured reports, severities and application decisions.

→ C / OBJECTS

Classes in C

Object interfaces built from structs, functions and opaque types.

→ DATA / CSV

US states and capitals

Searchable state, capital and coordinate data.

→ XML / BYTES

XML character encoding

UTF encodings, declarations and decoding errors.

→ CS / GRAMMAR

Linear grammar conversion

Convert a left-linear grammar through an NFA.

→ CS / GNF

Greibach normal form

Convert context-free grammar productions into GNF.

→

Query set / FAQ

Frequently asked questions

01What does “classic” mean on xFront?

It identifies durable XML, web architecture, semantic-web, formal-language and programming references inherited from the site’s earlier subject areas. The pages are maintained rather than presented as an untouched historical mirror.

02Are old xFront examples still technically current?

Maintained pages update obsolete terminology and add current limitations while preserving the original subject. Readers should follow the specification versions and processor assumptions stated on the individual page.

03Why do some classic links keep an .html suffix?

Those exact filenames have long been cited externally. Keeping the file URL avoids unnecessary redirect chains and preserves references whose path is part of the historical citation.

04Where should an unavailable legacy download lead?

When the original file cannot be recovered, the route should lead to the closest complete subject reference, not a generic homepage. The replacement must explain enough of the original topic to remain useful.