Z3 Theorem Prover is an open-source tool developed by Microsoft Research for checking the satisfiability of logical formulas. It supports various theories, including arithmetic, arrays, and bit-vectors, making it versatile for different applications in formal verification and software analysis. Z3 can automatically determine whether a given logical statement can be true or false, helping developers find bugs and ensure correctness in their programs. It is widely used in fields like formal methods, model checking, and program verification, providing a powerful resource for researchers and engineers working on complex systems.