This Festschrift volume is published in honor of Dexter Kozen on the occasion of his 60th birthday. Dexter Kozen has been a leader in the development of Kleene Algebras (KAs). The contributions in this volume reflect the breadth of his work and influence. The volume includes 19 full papers related to Dexter Kozen's research. They deal with coalgebraic methods, congruence closure, the completeness of various programming logics, decision procedure for logics, alternation, algorithms and complexity, and programming languages and program analysis.