Fluorescence microscopy is an essential and flexible tool for the study of biology, chemistry, and physics. It can provide information on a wide range of spatial and temporal scales. However, since the inception of light microscopy, diffraction has limited the size of the smallest details that could be imaged in any sample using light. Because much of biology occurs on molecular length scales, interest in circumventing the diffraction limit has been high for many years. Recently, several techniques have been introduced that can bend or break the diffraction limit. Localization-based methods introduced in 2006 have reached this goal and are now rapidly growing in popularity.