Xbox One/360, PS4, PS3, controllers are included. Any controller supported by SDL2 should be supported. GBEmu supports both keyboard and controller input. A ROM can also be opened from the command line. When running from the GUI an open dialog will be prompt to open a Game Boy ROM from the ROMs folder in the Home Diretory (see the Home Diretory). Finder, Windows Explorer) or the command line. GBEmu can be run from a standard GUI file manager (e.g. Right now it works on Mac, Windows and Linux.
Some distinctive features include a ROM debugger, a rewind system and easy-to-use quick save and restore slots. GBEmu (working title) is a Game Boy Emulator written in a C-style C++ (using some C++11 features like auto) and SDL2 (and a tiny bit of GTK3 on Linux).