Description
The J6502 is a modular emulator written in Java (Hence the 'J' is his name) that is capable of create any kind of virtual environment based on the core architecture of the MOS 6502 microprocessor, you can change almost anything, from the very instruction set to the devices attatched in the address bus. For more info about the usage of this library, check out the JavaDoc page.
Disclaimer
This project is not finished yet, you can use the code if you want, but do it at your own risk.
License
This project is under the GPLv3, you can read it here.