[mike_hearn]

Thanks for the correction re: C vs Rust.

W.R.T. memory usage that's true, but I think they've been making big improvements there lately with things like node inlining so it may not be true in the near future.

W.R.T. 2, what are you comparing against here? Is the TruffleRuby interpreter that much slower than the CRuby interpreter, also once you use the native image version? Because it seems like once it starts compiling the hotspots the program must get faster than a purely interpreted version. Whilst it may take minutes to reach peak performance for that engine, how long does it take to reach the same performance as YJIT?

W.R.T. 3, yes, but is it easier to fix that or to develop a new JIT from scratch? What is your solution to the C extensions problem for example? My understanding is that this is a major limit to accelerating Python and Ruby without something like Sulong and its ability to inline across language boundaries.