The Loss Simulation Model Working Party (LSMWP) , via the Dynamic Risk Modeling Committee, engaged a consulting firm to develop an open source simulation model of the processes of loss emergence and settlement, commonly known as loss development, that underlie the loss "triangles" and other statistics used to estimate unpaid claims. It has created a tool that researchers could use to generate claims that can be summarized into loss development triangles and complete rectangles which could then be used to test loss reserving methods and models. The new model is programmed in R and VB.NET, replacing a prototype model that was developed in APL which is not accessible today to most actuaries. The panelists will present the initial version of the new model and tests that have been performed.