GNU Astronomy Utilities (Gnuastro) is an official GNU package consisting of separate programs and libraries for the manipulation and analysis of astronomical data. All the programs share the same basic command-line user interface for the comfort of both the users and developers. Gnuastro is written to comply fully with the GNU coding standards so it integrates finely with the GNU/Linux operating system. This also enables astronomers to expect a fully familiar experience in the source code, building, installing and command-line user interaction that they have seen in all the other GNU software that they use. The official and always up to date version of this book (or manual) is freely available under GNU Free Doc. License in various formats (PDF, HTML, plain text, info, and as its Texinfo source) at http://www.gnu.org/software/gnuastro/manual/.
For users who are new to the GNU/Linux environment, unless otherwise specified most of the topics in Installation and Common program behavior are common to all GNU software, for example, installation, managing command-line options or getting help (also see New to GNU/Linux?). So if you are new to this empowering environment, we encourage you to go through these chapters carefully. They can be a starting point from which you can continue to learn more from each program’s own manual and fully benefit from and enjoy this wonderful environment. Gnuastro also comes with a large set of libraries, so you can write your own programs using Gnuastro’s building blocks, see Review of library fundamentals for an introduction.
In Gnuastro, no change to any program or library will be committed to its history, before it has been fully documented here first. As discussed in Gnuastro manifesto: Science and its tools this is a founding principle of the Gnuastro.