Hoffstaetter, G.H. JACoW Publishing Geneva, Switzerland This talk will specify the x-ray characteristics that can be achieved by Compton scattering off a high-brightness electron beam that ERLs make available. These are important parameters for x-ray users as well as for nuclear physics applications. The use of the Cornell BNL ERL Test Accelerator (CBETA) as an example layout for such a Compton source will be presented, including some accelerator physics details of CBETA’s design, construction, and commissioning. The talk will also highlight other applications that are enabled by unique features of ERLs.