Continued advances in optical projection lithography have enabled the pace of integrated circuit device miniaturization for the past two decades. High quality lenses have been fabricated with ever increasing numerical aperture, and the exposure wavelength has been reduced from 436 nm to 157 nm in four steps. Mask patterns have also been modified to compensate for diffraction in the imaging process. However, starting at the 45-nm technology node where the minimum pattern pitch is 90 nm, optical lithography might no longer be feasible or economical. New technologies will be required, and many new options have emerged as contenders to replace optical projection lithography. Some of these options use a mask and an imaging system, and they are termed next generation lithography (NGL) options. Others do not rely on a mask, and they are called maskless lithography (ML2). A third set of options use new paradigms such as imprint lithography or immersion of the wafer in a high index fluid. This paper will describe high level technology challenges and risks associated with these various approaches. Of the NGL techniques being considered, extreme ultraviolet (EUV) and electron projection lithography (EPL) are the most likely successors to optical projection lithography. Both of these techniques will be reviewed with more emphasis. EUV has more worldwide support, and the presentation will detail progress and challenges in fabricating low defect masks, high power sources, resists and exposure tools.