This paper presents the current "state of the art" of Post Keynesian modeling, as well as the most important issues raised by it. We first present a new formal statement of Keynes's model. We then analyze the three most important classes of Post Keynesian contemporary models: the Kaleckian models of growth, the Minskian models showing the destabilizing effects of financial variables on the economy, and the path-dependent models insisting on the nature of time in economics, and on the absence of any "natural" anchor. We argue that, whereas the current Post Keynesian models have a lot in common with Keynes's model, none of them encompass all its rich and realistic properties, and a synthetic dynamic Post Keynesian model is desirable, and has still to be framed.