&gt; Even if one did, you&#x27;re either relying on browser creators to include a runtime, or you have to patch one in, Flash-style.<p>This would actually be the perfect use-case for Google&#x27;s Native Client, if other browsers would bother to support it.<p>The arguments against webapp authors writing their app in NaCl are probably valid. But those arguments don&#x27;t apply to the case where the &quot;apps&quot; are run times, there are only a common ones floating around, and people pull them in by URL in order to script against them.<p>Interestingly, this would solve one additional pain-point: every script would have the particular <i>ABI version</i> of the runtime it was coded against &quot;locked&quot; into it, in the same sense as a Ruby&#x2F;Node dependency-lock file. So the runtimes themselves could be in very heavy flux version-to-version, as long as they kept old ABI-lines around and patched with security-updates.