The Topic Maps Constraint Language (TMCL) is a language for defining schemas and constraints on topic map models. Specifically, TMCL can be used to constrain instances of Topic Maps Data Model. The constraint language provides a constraint model, related validation semantics, and CTM syntax templates for authoring constraints. The latest draft is available here.

A TMCL validator is a tool which validates a TMAPI topic map against a schema and returns a list of invalid constructs together with a description what constraint was violated.

The Topic Maps Lab is proud to announce that our TMCL validator implementation in Java is now open source under the Apache Licence 2.0. The code is available at Google code. For getting started we recommend you .

The TMCL validator is packaged with the TMCL loader. This small tool loads a TMCL file including all TMCL related CTM syntax templates, which are usually not part of the schemas but needed by a validator.

The TMCL validator is stable and production-ready. Nevertheless it is an ongoing project. We cordially invite all developers to use the validator in their projects and file issues if an unexpected behaviour or new ideas occur. Everybody with an deep interest in the further development of the TMCL validator is invited to support the project.