GSnap is a tool for analyzing, viewing, and manipulating snapshots from galaxy simulations. It is licensed under the GNU General Public License 3.0, so you can freely access the code and become a contributor. The code is written in C++11 and depends only upon the Qt Framework, the standard C++ library, and (optionally) OpenMP. It is compatible with GNU/Linux, Mac OS, and Windows operating systems. In principle, it should work on any OS supported by Qt. However, the target OS is GNU/Linux.
GSnap was initially written to measure the velocity dispersion of particles in galaxy simulations, but it is now useful for interactively rotating and zooming snapshots, measuring distances between objects (and sizes of objects), interpolating between snapshots, manipulating / editing snapshots, and creating high quality visualizations of the stars and gas in galaxy simulation snapshots. In addition to a GUI, GSnap offers a powerful command line interface, which allows the user to operate the program from a script, and a built-in ECMAScript interpreter, which allows the user to potentially extend GSnap’s functionality. Currently, only very specialized GADGET-2 and GADGET-3, type 1 snapshots are supported, however, adding a new file format is a fairly straightforward task.
GSnap was developed by Nathaniel Stickley as part of his Ph.D. research project at the University of California, Riverside. He encourages others to contribute to the project, to keep it alive and improve it. Financial support for GSnap was provided by NASA through a grant from the Space Telescope Science Institute (Program AR-12626), which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. Additional funding was also provided by NSF under grant number AST-0507450.