copy.sh has the advantage of being x86-compatible and can run many different Linux distributions. However, this CPU choice also makes it quite complex and relatively slow (not sure, if this is still correct).

My own OpenRISC CPU emulation fits into just 1,500 lines of code, and I optimized every single line. To make it work, I had to compile my own Linux distribution completely from scratch. I stopped working on it about eight years ago, but I’ve completed a dozen other successful projects since then.

I’m still very proud that nearly every browser-based Linux emulator, including JSLinux and copy.sh, uses my 9p-virtio- filesystem approach. It makes running complex Linux distributions in the browser much simpler.

Overall, my thoughts about copy.sh’s work are entirely positive.