For the sake of completeness, PEP8 actually says 'Use 4 spaces per indentation level'

He's not changing anything, and he's not relying on weird browser implementations - it's part of the spec.

I hate unnecessary semicolons too. Though I deal with them by including them everywhere, but making them hard to see in my editor ;)

alternatively, use JSLint

I much prefer JSHint. JSLint is draconian, and has some borderline insane decisions (it complains if you don't declare your vars at the top of a block—is this 1980?).

And yes, I realise that some of these options can be turned off—but JSHint has better defaults.

There is a reason for the insanity you are complaining about. The vars are effectively hoisted there by the interpreter anyway, by pulling them to the top of the block you remove a possible point of confusion, and more importantly a possible point of bugs.

jshint is great. Putting this in ~/.jshintrc makes it a lot more sane:

    {
      "browser" : true,
      "node"    : true,
      "undef"   : true,
      "eqeqeq"  : true,
      "noarg"   : true
    }