title: Is strict mode more performant?
body: <p>Does executing javascript within a browser in 'strict mode' make it more performant, in general? Do any of the major browsers do additional optimisation or use any other techniques that will improve performance in strict mode?</p>
  
  <p>To rephrase slightly, is strict mode intended, amongst its other goals, to allow browsers to introduce additional optimisations or other performance enhancements?</p>