Precision Kaon and Hadron Physics with KLOE

— We describe the KLOE detector at DAΦNE, the Frascati φ–factory, and its physics program. We begin with a brief description of the detector design and operation. Kaon physics is a major topic of investigation with KLOE thanks in part to the unique availability of pure KS,KL, K ± beams at a φ–factory. We have measured all significant branching ratios of all kaon species, the KL and K ± lifetimes and the K → π form factor's t dependence. From the measurements we verify the validity of Cabibbo unitarity and lepton universality. We have studied properties of light scalar and pseudoscalar mesons with unprecedented accuracy. We have measured the e + e − →π + π − cross section necessary for computing the major part of the hadronic contribution to the muon anomaly. The methods employed in all the above measurements as well as the φ leptonic width, precision mass measurements and searches for forbidden or extremely rare decays of kaons and η-mesons are described. The impact of our results on flavor and hadron physics to date, as well as an outlook for further improvement in the near future, are discussed.