Now that programmable logic devices with gate densities of over 100K gates ape commonly available, field programmable gate array (FPGA) and complex programmable logic device (CPLD) designers are adopting new design flows to take advantage of their power. These design flows are based on a high level design methodology with advanced logic synthesis technology, In addition, they require other sophisticated design tools that, in the recent past, were exclusively part of the ASIC design realm, this paper discusses the new challenges that programmable logic designers face and the resent developments in design tools and design flows to satisfy their requirements.