Latest commit 969eabb Jan 16, 2016 @pavelfatin pavelfatin Compatibility with Arduino's core HID / Mouse / Keyboard libraries
The following collisions resolved:

hid.h -> usbhid.h
hid.cpp -> usbhid.cpp
HID -> USBHID
HID_BOOT_PROTOCOL -> USB_HID_BOOT_PROTOCOL
HID_PROTOCOL_NONE -> USB_HID_PROTOCOL_NONE
HID_PROTOCOL_KEYBOARD -> USB_HID_PROTOCOL_KEYBOARD
HID_PROTOCOL_MOUSE -> USB_HID_PROTOCOL_MOUSE

As a result, it's possible to use the library together with Arduino's bundled HID / Mouse / Keyboard libraries (Leonardo, Micro, or Due).

https://www.arduino.cc/en/Reference/MouseKeyboard