We are currently working with several government agencies that wish to expose data via the NIEM standard. The MetaMatrix product is being used to map current data sources into NIEM compliant views of that data without ever writing a line of code.
We have a NIEM specfic example that demonstrates this capability by using a pre-fab Derby database. Our product is downloadable for a free trial for anyone who might be interested. Here is the link to the example: