Euclid is a tool for manual labelling of data - sets, such as those found in Deep learning systems that employ Caffe. This includes systems like DIGITS, and YOLO. It is an object / class labelling tool for machine learning frameworks.
This tool runs on Linux and Windows, and is based on Python 2.7/Tkinter. Though the UI is a bit clunky it is functional at this point.
Label format support: