WARP is a multidimensional intense beam simulation program being developed and used at the Heavy Ion Fusion Virtual National Laboratory, which currently includes LBNL, LLNL, and PPPL, and at other sites, most notably NRL and the University of Maryland. It allows flexible and detailed multi-dimensional modeling of high current beams in a wide range of systems, including bent beam lines using a ”warped” coordinate system (from which the code derives its name). It is being designed and optimized for heavy ion fusion accelerator physics studies. At present it incorporates a 3-D description, an axisymmetric (r, z) description, a transverse slice (x,y) description, a simple envelope model used primarily to obtain a well-matched initial state, and envelope/fluid models used for scoping and design. The flexibility and detail of WARP modeling can be seen in recent movies of HCX and merging-beamlet simulations.