This is the Basilisk II color 68K Mac emulator running in the web browser. A hack by @ur_friend_james. Source on GitHub.
Please note that everything you modify in this VM will be discarded, nothing is saved.

Also try out: System 7.5.3 with HyperCard 2.1 | System 7.5.3 with SimCity 2000 + URK | Mac OS 8.1 with SimCity 2000 + URK |

WARNING: This requires a modern browser feature called SharedArrayBuffer. Make sure to use Firefox 79.0 or newer.

This may take a minute or two to download all the files needed, PLEASE BE PATIENT.