IWAVE is a framework for time-domain regular grid finite difference and finite element methods. The IWAVE package includes source code for infrastructure component, and implementations of several wave physics modeling categories. This paper presents two sets of examples using IWAVE acoustic staggered grid modeling. The first set illustrates the effectiveness of a simple version of Perfectly Matched Layer absorbing boundary conditions. The second set reproduce illustrations from a recent paper on error propagation for heterogeneous medium simulation using finite differences, and demostrate the interface error effect which renders all FD methods effectively first-order accurate. The source code for these examples is packaged with the paper source, and supports the user in duplicating the results presented here and using IWAVE in other settings.