Explaining StGermain: An aspect oriented environment for building extensible computational mechanics modeling software
 The use of seismic imaging techniques is widespread. Numerous three-dimensional (3-D) tomographic models have been presented over the last 30 years and subsequently analyzed by a wider community of seismologists, geodynamicists, mineral physicists, and geochemists. However, platform-independent, open source, user-friendly software for interactive exploration of tomographic models does not exist. Here, we present a package for interactive visualization, analysis, and presentation of tomographic models. Using a set of four Matlab programs, multiscale tomographic models can be explored in Cartesian or spherical coordinate systems; data subsets can be extracted and combined; publication-quality figures can be produced; and Virtual Reality Modeling Language (VRML) models can be produced for 3-D visualization and publication on the World Wide Web. This type of freely available software package will encourage the distribution of tomographic models in a standardized form for independent peer review by the research community.