SHLURD is an attempt to support very limited natural language understanding for small worlds a la SHRDLU. It's implemented in Scala using Stanford CoreNLP as the basis for its parser.
(So far, SHLURD's understanding is nowhere near as powerful as that of SHRDLU.)
The first practical supported small world domain is OpenHAB home automation.
We also use the bAbI tasks from Facebook Research as a QA set.