The x‐ray source is a critical part of any x‐ray lithography system since the source characteristics directly affect resolution, alignment, and throughput. Conventional electron bombardment sources, using either stationary or rotating anodes, are now in wide use. However their poor efficiency, low brightness, and uncollimated nature makes them doubtful candidates for high throughput lithographic systems. Several possible alternative sources have been discussed in recent years. They fall into two broad categories: accelerated charged particle beams and high temperature plasmas. The first category includes the synchrotron and related devices such as wigglers. Although these are large and costly installations, they are excellent sources of soft x‐rays and have many advantages as lithographic sources. The second category contains many different systems capable of producing dense, high temperature plasmas. Some of these have been shown to have promise as compact, efficient, high brightness x‐ray sources. Devices in each of these two categories will be discussed and the relative advantages and disadvantages of each as a source for x‐ray lithography will be outlined.