The recent emphasis on low-cost high-end servers and desktop workstations has resulted in a renewed interest in the development of high-performance air-cooled systems. A new generation of advanced heat sink designs capable of dissipating up to 105 W/m2 have been proposed and developed. Better manufacturing tolerances, lower defects, and an improved understanding of card and enclosure effects have been attained and shown to be critical to achieving the desired thermal performance. Advanced internal thermal enhancements, encompassing high thermal conductivity adhesives and greases have also been implemented. This review article covers recent developments in heat sink designs and applications intended for high-end high-power dissipation systems. A review of recent studies of card effects in the thermal enhancement of electronic packages is also presented. In certain applications the card heat-sinking effect can play a major role in the thermal management of a package, accounting for more than 50 percent of the total power dissipation of the package.