Worldwide there is a trend to use diffusion bonding for more and more applications, for example for optical components, micro devices and heat transfer elements. Despite that the market for diffusion bonded product is still small today, more than 30 companies offer diffusion bonding systems worldwide. These systems are different, starting from basic concept and type of machine, the principle of heat input and force application. In the presentation an overview of commercially available diffusion bonding system concepts and their differences is given.