Augmented Reality (AR) based training is a current trend being investigated by several research efforts applying specific new concepts such as educational games and platforms for ICT enabled learning experiences. Hence, due to the fact that recreational computer games are extremely popular with people of any age, there is no doubt that 3D training environments determine the trend in the future of training assistance. In this context AR environments can offer the possibility for trainees to interact with the real environment (e.g. a complex industrial machine) and with virtual objects that are linked to the real environment and provide additional information. This requires the development of training platforms that offer a flexible and coherent technical infrastructure, which supports the use of Augmented Reality with different training settings in different training application domains.