The field of High Energy Physics has evolved dramatically in the recent years with physicists' hot pursuit of answers to many fundamental questions, such as the existence of dark matter, dark energy and extra dimensions. Such endeavors are constantly imposing enormous challenges on particle detectors capabilities in order to meet the exceptional calorimetry requirements needed by the current High Energy research. To meeting such exceptional calorimetry capabilities, a new concept in scintillator-based hadron calorimeters is envisaged and realized: The Integrated Read-out Layer (IRL). This concept has been successfully test and proven capable of meeting such requirements, having the potential to be implemented in any accelerators to be built in the future. An in-depth evaluation of an prototype IRL concept is presented in this book.