Multi-Schema Validator Toolkit
April 16, 2026 ยท View on GitHub
The Multi Schema Validation toolkit is a Java based toolkit consisting of 8 different submodules.
The core module is the Multi-Schema XML Validator (MSV) for the validation of XML documents against several kinds of XML schemata.
The core supports RELAX NG, RELAX Namespace, RELAX Core, TREX, XML DTDs, and a subset of XML Schema Part 1.
Most outstanding is the design of MSV core using the Abstract grammar model (AGM). This is a schema-independent grammar model. All supported schemata are parsed into this internal representation. This model, coupled with the grammar reader, may be useful for other applications. For instance, two use cases are the generation of source code using schema2template or the ODF Validator.
The builds of all MSV sub-projects were tested successfully using OpenJDK 11, 17, 25 and Oracle JDK 26 on Windows (intel) & macOS (arm).
Overview Sub Project
The MSV toolkit consists of eight sub-projects, the main projects in bold. Each sub-projects has its own directory, its own build script, etc.
| sub-project | description & dev guide reference |
|---|---|
| xsdlib | XML Schema Datatype (XSD) Library An implementation of W3C XML Schema Part 2 (see xsdlib JavaDoc). |
| msv core | Multi-Schema XML Core Validator A schema model and validator implementation (see MSV Core JavaDoc). Dependent on XSDLib and testharness. |
| generator | XML Instance Generator A tool that produces valid XML documents by reading a schema. Dependent on MSV. |
| schmit | MSV SCHema In Transformation XSLT add-on (Schmit) XSLT Extension For Schema Annotation. |
| relames | Multi-Schema XML Validator Schematron add-on An experimental implementation of RELAX NG + Schematron validation. Dependent on MSV. |
| rngconverter | RELAX NG Converter reads a schema and produces an equivalent RELAX NG schema. Dependent on MSV. |
| tahiti | Data-binding implementation |
| trexconverter | TREX Converter Reads a schema and produces an equivalent TREX pattern. |
Installation
All subprojects are all available from Maven Central.
Contributing
You have three options if you have a feature request, found a bug or simply have a question about System Rules.
- Write an issue. (soon available)
- Create a pull request. (See Understanding the GitHub Flow)
- Write a mail to our mailing list (soon available)
The basic coding style is described in the
EditorConfig file .editorconfig.
Development Guide
The MSV Toolkit development documentation can be found at our GitHub pages.