Significant size reduction, works on both emulators and real hardware. 3. NKIT.ISO
A "highly compressed" ROM is a game file that has undergone specific data reduction techniques to strip away this useless dummy data, compress the core game files, and pack them into a much smaller archive format (such as .RAR , .7z , .ZIP , .RVZ , or .WBFS ).
The Ultimate Guide to Legend of Zelda: Skyward Sword ROM Highly Compressed