An emulator is an unofficial platform that is supported on the official leaderboards. Emulators are the second fastest supported platform. They have the same load times as N64, but do not lag at all during gameplay.
The only permitted emulator version is Project 64 v1.6. Later versions of Project64 are banned from the leaderboards due to load time inconsistency. Additionally, OpenEMU and Mupen64plus are also allowed so that Mac and Linux users can play too. Any of these emulators can be used on any platform, but it is preferred that if you are on Windows you stick with Project64
N64 ROMs are stored as either .z64 or .n64 files (Never as an exe file). They can be legally obtained by using a cartridge dumper to copy the ROM from your own Nintendo 64 cartridge. To verify that you have the correct ROM, you can compare your ROM's MD5 hash to the following:
Distributing ROM files is illegal, and as such it is up to you to legally obtain your own ROM.
While any version of Super Mario 64 can be played on Emulator, there are only 2 relevant versions (since the benefits of shindou are irrelevant due to the fact that lag is not present on emulator).
This is the first Japanese release. This version has a shorter intro cutscene, less text overall, and small differences in a few stages. it is faster for 1 Star, 16 Star, and 120 Star
This is the North American release. Text boxes scroll faster and 15 star MIPS runs slower in this release. It is faster for 0 Star and 70 Star
The Emulator setup guide is a comprehensive walkthrough of the process to download install the proper emulator version (Project 64 v1.6) and choosing the best setting and plugins to maximize gameplay and visual performance.
Alternatively, you can download a build of Project64 v1.6 from the resources tab on the official leaderboard