This paper introduces and summarizes the main progress made in the research of Yb-doped rare-earth calcium oxyborate (Yb∶ReCOB) crystal lasers in recent years. It includes continuous-wave lasers, acousto-optic Q-switching, passive Q-switching with Cr ⁴⁺∶YAG, GaAs, or two-dimensional materials as saturable absorber, Saturable absorber mode-locked, Kerr-lens mode-locked, and self-frequency doubling green and yellow lasers. This type of Yb∶ReCOB crystal shows great potential for many all-solid-state laser applications with different modes of operation.