Try OpenGeoMesh
A test instance of the OpenGeoMesh protocol is available at demo.opengeomesh.org. Use this instance to test OpenGeoMesh and to test your own instances or the compatibility of your own implementations. The Test-Setup is also offered as Docker Compose Stack and can be run locally or used as starting point for your own deployments.
The following user can be used for testing; individual access can be requested via info@opengeomesh.org. The test instance is reset in reqular intervals.
User: test
Password: testtest