[Estragon]

Is nock designed to run untrusted, potentially hostile code with guaranteed identical results on all platforms?

I'm looking for a virtual machine (or NaCl-like sandbox) which does this.

Edit: To anyone who downvoted me, could you please let me know why?

[lexcorvus]

I'm just speculating, but the HN upvote/downvote arrows are tiny, and it's easy to click on the wrong one accidentally. (This is especially true on tablet devices.) Your comment clearly doesn't deserve a downvote, though, so I've thrown you an upvote to help make up for it. :-)

[urbit]

Yes - although actually achieving this result in practice (and efficiently) takes a lot of doing right.

[Estragon]

Thanks. How close are you to achieving that?

[urbit]

Nock works perfectly, of course, but it's poorly optimized. The various "jets" (optimized implementations) in our runtime haven't been adequately tested and there are probably a few corner cases, errors, etc, where the behavior doesn't match. Even the new Nock runtime (I just rewrote more or less the whole interpreter) is probably a little too bound to Urbit specifically.

But the system has been self-hosting for quite some time, and there's certainly no doubt that the general approach works...