I would argue on the most government is on the .net part. I have been over 12 departments now, large scaled java development is everywhere. I didn't have to much chance since 2000 to practise my .net skills, I was forced to stay with java. There are lots of small departments is on .net, but large ones like CBSA, RCMP, CRA, CIC, PWGSC, Health Canada all have projects worth billons on the Java. The largest development I know so far that is using .net is the ocean and fishery.