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"CTools & SZS Modifier"
The WiiCoder is a mod kit (modification toolkit) more correctly known as the SZS modifier, which would later include a library called CTools that contains a number of programs designed to edit and modify the game files for Nintendo Wii, although it’s mostly used to supplement the SZS Modifier. This program can alter and adjust the SZS files of Mario Kart for Wii; SZS files are read as archives and store data regarding game play and profiles; in effect, save data for the game. The SZS Modifier has a few notable features, including the ability to perform texture and model hacks to Mario Kart Wii, such as by importing textures and models from other Wii games that uses an SZS game file (in effect this can also be used vice versa, in that users can export Mario Kart Wii models to other games that use an SZS data storage). The SZS Modifier requires at least a .NET Framework 2.0.
Both the CTools and the SZS Modifier, written by Chadsoft, are discontinued, though the mod that resulted from these tools is still available, called CTGP Revolution.