The entire series features an open-ended plug-in architecture, allowing new scenarios to be written by users. This technology is based on the Macintosh resource fork format, making it possible to develop plug-ins without using any purpose-designed editors (though several editors exist and are popular since they make the task much easier). Since Windows does not support resource forks and it is therefore impossible to preserve them when transferring files to Windows-based computers, an alternate format and a conversion system were devised for the Windows version of the game.