[epi8]

Running this on the client side would require a C++ compiler in javascript, right? I don't know much about web dev.

[azakai]

Yes, there are demos of such things. For example, these two:

http://kripken.github.io/clangor/demo.html

http://kripken.github.io/llvm.js/demo.html

A bit old by now, but the first compiles C++ into LLVM IR, the second LLVM IR into JS and runs it. All of that happens clientside.

[DannyBee]

Or compiling gcc to nacl/asm.js