The file structure of a mod is basically the same as that of the data folder. If it's an existing name, the old entity is replaced. If a mod specifies an entity with a new name, it's added. Mods work by adding and replacing entities. The JSON definition for a cannon inside the ModuleType folder: Inside the data folder, each entity type has its own folder, which contains JSON files, which contain lists of entities. The game's data is organized into loadable entities which are stored in the data folder in the game's install folder. The dot prefix means that it's hidden by default.

Mac: The user folder is called AirshipsGame and is in your Documents folder in your home folder.

A folder will appear, containing a folder called AirshipsGame.

Windows: Open the start menu, type %APPDATA%, and press enter.

Mods installed from Steam can be found in steam/mods.

Mods are installed in the mods folder in the game user folder. To find the game install directory in Steam, right-click on the game in the Steam library, choose 'Properties', go to the 'Local Files' tab and click 'Browse Local Files'. On Linux, use whatever standard text editor - xed or pluma or whatever - is installed by default.

Notepad++ for Windows, or TextMate for Mac.

They're all free and mostly open source, and available for Windows, Mac, and Linux: Pretty much any text editor and graphics program will do to create mods, but here are the programs I use. Graphics are stored as PNG files, and sounds as OGG, which is an open source audio format similar to MP3. All game information is stored in JSON, which is a standard text-based data format a bit like XML. Creating mods for Airships requires no programming skills.

Where are steam mods stored