Super-resolution imaging methods now can provide spatial resolution that is well below the diffraction limit, approaching virtually molecular resolution. They can be applied to biological samples and provide new and exciting views on the structural organization of cells and the dynamics of biomolecular assemblies on wide timescales. These revolutionary developments come with novel requirements for fluorescent probes, labeling techniques, and data interpretation strategies. Researchers from across the scientific spectrum are involved in designing improved tools and solving previously intractable problems using super-resolution techniques.