Reality is hard to simulate. A standard approach is to write down idealized models and simulate these instead. But as computational methods improve, the hope is to cut out the middle-man and simulate real systems directly. I will describe extensions to the density matrix renormalization group (DMRG)---the most powerful method for simulating quantum systems in 1d---which allow us to treat continuum systems, long-range interactions and finite temperature effects. This allows us to get essentially exact results for systems which could previously be studied only with density-functional methods or in cold atom/molecule experiments.