[cxr]

Surely by "re-run" you mean "try to re-build". If you write something that runs in the browser today (and you're not doing something dumb like using experimental or otherwise non-standard APIs), chances are extremely high that it will still work in two years. The browser is one of the most consistent, interoperable, stable software platforms that the industry has managed to produce.

[ramijames]

Yes, that's what I mean, thanks.