To install the game simply run the setup file.
* * * * * * *
You can also browse the most recent code available via a web based interface.
The following libraries are required to compile from source:
1. Extract the archive to wherever you want to install the game. It will create a directory named "galaxyhack".
2. Go into the "src" subdirectory.
3. If you have all the required libraries installed in the standard locations you might be able to compile the program just by typing "make", but then again, maybe not.
4. Either a) move the compiled "galaxyhack" out of the "src" subdirectory and into the same directory as all the game data, or otherwise edit the settings file to point to the data file location (see here), and then put the settings file in ~/galaxyhack and the binary wherever you want to.
The code is released under the GPL. In short: though you are free to redistribute the source code as much as you wish, and even use it in your own projects, anything the code is used for must also be made available under the GPL.
Please note that the art and music from the game is not released under the GPL. Though you are free to redistribute the game in its entirity, if you wish to use their work in a project of your own then you will need to ask permission from the authors (see the credits).