The Materials Visualization Environment (MatViz) is a new project to build an open source, cross platform desktop application for materials tomography, focus on the output of S/TEM tomography experiments. This is a collaborative project between Kitware and Cornell University, primarily involving Marcus D. Hanwell and Utkarsh Ayachit at Kitware, and David A. Muller and Robert Hovden at Cornell University.
As present you can access the dashboards here, where you can click on the small yellow box to download binary installers (Windows 32 bit, Windows 64 bit and Mac OS X 64 bit). You can also access the source code respository here on GitHub. These locations may change in the future as the project is at an early stage.