Browsercraft allows unmodified Minecraft to run in the browser through CheerpJ, a Java runtime. It is not Minecraft Classic or the Bedrock Edition but the original game without modifications. CheerpJ, a Java Virtual Machine in WebAssembly, enables Java applications to run in the browser without source code changes. The project is ongoing, with some features like audio not yet supported. Programmers are welcome to contribute to fixing these issues through Discord and GitHub.
https://browsercraft.cheerpj.com/