The drive to achieve low emissions from gas turbines has been an ongoing challenge for over 30 years with the reduction of NOx levels representing the most difficult issue. Catalytic combustion represents the technological approach that can achieve the lowest level of NOx in the range of 3 ppm and lower depending on the combustion system design. The program to develop a catalytic combustion technology that can achieve ultra low levels of NOx, CO and unburned hydrocarbons (UHCs), applicable to a wide range of gas turbine systems and with long term durability is described. The technological approach is to combust only a portion of the fuel within the catalyst with the remaining fuel combusted downstream of the catalyst allowing the catalyst to operate at a low temperature and thus obtaining good long term catalyst durability. This catalytic combustion approach is then applied to a 1.4 MW gas turbine to demonstrate feasibility and to obtain real field experience and to identify issues and areas needing further work. The success of this demonstration, lead to a commercial combustor design. This combustor and the final commercial package is described and the performance specifications discussed. (C) 2003 Published by Elsevier Science B.V.