Hibernate Validator

Move from JAXB to Stax for parsing the XML descriptors as JAXB will be removed of JDK 11 (HV-1577)
Explore taking some distance from the reflection API (e.g. dealing with Type is rather confusing, replace some of the types with memory-friendly counterparts (Method?), do not rely on TypeVariable). Note that it might also help with the future usage of Jandex for annotation discovery.
Provide an SPI for making the retrieval of bean properties more flexible, allowing to support models not following the JavaBeans conventions, e.g. types generated by Immutables which will use property() instead of getProperty() (HV-1363)
Add support for JSON validation at the root level (i.e. validating a root JSON object) and at the property level (i.e. validating a JSON property of a given bean)
Support JDK 10 and 11

Usage of method handles for accessing bean states (HV-1226)
Explore usage of ResourceBundleProvider for obtaining validation error messages from other modules
Providing Hibernate Validator with JDK 9 module descriptors

Explore the ability to validate an object and a list of changes (BVAL-214)
Explore support for constraint ordering (BVAL-248)
Explore support for other models than JavaBeans (HV-1000)
Explore the usage of Jandex (a Java annotation indexer and offline reflection library) to build the metadata (HV-644)
Explore message interpolators receiving several locales (HV-1436)

Be able to define constraint on properties using lambdas (ie without constraint annotations)

Provide an HTTP endpoint which allows to validate single properties and also exposes constraint metadata via JSON (HV-1500). Web applications can integrate that endpoint to allow client-side validation of their models.

Taking into account new places where constraint annotations can be placed (HV-879)
Taking into account XML configuration (HV-308)