[jeroenhd]

Agreed, without the risk of memory corruption and the associated security risks, C can be used without too much hesitation (as long as your complicated pointer code doesn't break your own data structures and mess up your program, of course!).

I think it would be a challenge to compile all dependencies for a fully features C program into WASM, but if you pick your libraries well, C could be an excellent language for speeding up complex calculations in Javascript.