FCEUX is one of the best emulators NES consoles (in the vernacular - Dendy). The program is completely free and is distributed under the GPL2 license. The interface is in English.
- support a huge number of mappers and ROMs NES and FDS (for the latter you need the original BIOS!)
- support .zip
- integrated player .nsf
- support for OpenGL
- support scripts written in Lua
- ability to take screenshots
- recording and playback of passages in the format .fm2
- gamepad support and the ability to use the mouse as a light gun
- support for saving and so on.
You can install it using software Center or by running the command in terminal:
sudo apt-get install fceux
Also, you can always download the source code from the developer's site.