This is a basic emulator for the CHIP-8 programming language. I want to thank Laurence Muller for his excellent article on how to write a basic CHIP-8 emulator, as it has been very helpful in learning how an emulator works and how it can be written.
Run it with java Main.class [rom_file]. Programs can be paused by pressing p, otherwise keybindings are the same as in the linked article; that is: 1234 qwer asdf zxcv.