New in version 4.0:

• new, improved index format
• transitional (backward-compatible) new API v4, preparing for a future, clean API v5
• support for (dependency) relations
• support for parallel corpora
• better XPath support using Saxon for indexing (available before, now fully featured)
• experimental support for using BlackLab with Solr, which should eventually make distributed corpora possible

Includes some breaking changes to the Java API.