Description Alphagamma stands for the combination of a Stirling- alpha principle with a gamma principle. The new engine technology is characterised by extremely reduced piston forces, because compared to conventional Stirling engines, where typically one piston produces work and the other one consumes work, both pistons can create positive work. The low normal forces of the piston allow oil-free and long-lasting operation with coated piston skirts. Moreover, a special burner was developed that can cleanly burn lean gases with a methane content of as little as 14%. The disposal of waste gases or the use as a quiet auxiliary power unit in vehicles are just two of the many possible applications of the low-maintenance and highly efficient drives.