Browsix

"Run C, C++, Go and Node.js programs as processes in browsers, including LaTeX, GNU Make, Go HTTP servers, and POSIX shell scripts.

Programs written to run on conventional operating systems typically depend on OS abstractions like processes, pipes, signals, sockets, and a shared file system. Compiling programs into JavaScript, asm.js, or WebAssembly with tools like Emscripten or GopherJS isn't enough to successfully run many programs client-side, as browsers present a non-traditional runtime environment that lacks OS functionality. Porting these applications to the web currently requires extensive rewriting or paying to host significant portions of code in the cloud.

Unmodified C, C++, Go, and Node.js programs run as processes on Web Workers, executing in-parallel with the main browser thread – no need to worry about long-running computations blocking event-handling or page rendering.

By working at the lowest levels of abstraction, Browsix provides shared resources to multiple language runtimes, just as traditional operating systems enable running programs written in a host of languages.

By enabling a large class of programs (including legacy codebases) to run in-browser, Browsix can free you from the chore of sandboxing and load-balancing programs server-side."

https://browsix.org/