VisIt (Visualization and Data Analysis for Mesh-based Scientific Data) is an interactive, parallel visualization and graphical analysis tool for viewing scientific data on Unix and PC platforms. While this repo has been around for a while enjoying a robust developer community, it is newly housed on GitHub. Stay up to date with the latest release notes.
With VisIt, users can quickly generate visualizations from their data, animate them through time, manipulate them, and save the resulting images for presentations.
VisIt contains a rich set of visualization features so that you can view your data in a variety of ways. It can be used to visualize scalar and vector fields defined on 2D and 3D structured and unstructured meshes. VisIt was designed to handle very large data set sizes in the peta-scale range, yet it can also handle small data sets in the kilobyte range.