The actual OQL implementation comprises of the query engine and the visual console embedded within the HeapWalker. The visual console offers basic OQL language syntax highlighting and code completion. It also provides a contextual help linking to the rather exhausting jHat OQL documentation explaining the basics of the OQL as well as providing many working examples. The query results are bound back to the rest of the HeapWalker for the ease of navigation.
Demo of the OQL integration can be seen here.