Simulation has emerged as an important method for evaluating new ideas in both uniprocessor and multiprocessor architecture. Compared to building real hardware, simulation provides at least two advantages. First it provides the flexibility to modify various architectural parameters and components and to analyze the benefits of such modification. Second, simulation allows for detailed statistics collection, providing a better understanding of the tradeoffs involved and facilitating further performance tuning. This document describes RSIM - the Rice Simulator for ILP Multiprocessors (Version 1.0). RSIM is an execution-driven simulator primarily designed to study shared-memory multiprocessor architectures built from state-of-the-art processors. Compared to other current publicly available shared-memory simulators, the key advantage of RSIM is that it supports a processor model that aggressively exploits instruction-level parallelism (ILP) and is more representative of current and near-future processors. Currently available shared-memory simulators assume a much simpler processor model, and can exhibit significant inaccuracies when used to study the behavior of shared-memory multiprocessors built from state-of-the-art ILP processors. A cost of the increased accuracy and detail of RSIM is that it is slower than simulators that do not model the processor. We have used RSIM at Rice for our research in computer architecture, as well as for undegraduate and graduate architecture courses covering both uniprocessor and multiprocessor architectures.