Joel's nesemu1.cpp port to Java:
http://bisqwit.iki.fi/jutut/kuvat/programming_examples/nesemu1/
http://www.youtube.com/watch?v=y71lli8MS8s
http://www.youtube.com/watch?v=XZWw745wPXY
- No input
- No sound
- Actual screen rendering is broken
So it's useless.
I did accomplish one thing though, the reason why the port was made in the first place: java -Xint can't handle it.