Superallowed Nuclear Beta Decay: a Window on the Weak Interaction

For more than 50 years, superallowed 0$^{+}\to $0$^{+}$ beta decay has been used to probe the weak interaction. By now, more than a dozen such superallowed transitions are known to $\sim $0.1{\%} precision. The results provide an exacting confirmation of the Conserved Vector Current hypothesis and are also a key component in the most demanding available test of the unitarity of the Cabibbo-Kobayashi-Maskawa matrix. This talk will present the current status of measured results, describe some contemporary experiments and indicate the prospects for future improvements.