I will discuss supergroup gauge theory with emphasis on the following aspects: instanton counting, Seiberg-Witten geometry, brane construction, realization in topological string and intersecting defects, Bethe/Gauge correspondence, and quantum algebraic structure. Based on joint works with H.-Y. Chen, N. Lee, F. Nieri, V. Pestun, and Y. Sugimoto (mostly summarized in https://arxiv.org/abs/2012.11711).