Apps can use JavaScriptCore, and JavaScriptCore can use JIT, but these can&#x27;t happen together, because third-party apps aren&#x27;t permitted to execute writeable memory.<p><a href="http:&#x2F;&#x2F;stackoverflow.com&#x2F;questions&#x2F;22281265&#x2F;is-javascriptcore-framework-on-ios-7-using-jit-compilation" rel="nofollow">http:&#x2F;&#x2F;stackoverflow.com&#x2F;questions&#x2F;22281265&#x2F;is-javascriptcor...</a>