function ajax(url, post_parameters, callback, data)
  {
  	var http = new XMLHttpRequest();
  	if (http != undefined)
  	{
  		http.open(post_parameters == '' ? 'GET' : 'POST', url, true);
  		http.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
  		http.onreadystatechange = function()
  		{
  			if (callback != null)
  			{
  				callback(this.readyState, this.status, this.responseText, data);
  				// readyStates: UNSENT = 0, OPENED = 1, HEADERS_RECEIVED = 2, LOADING = 3, DONE = 4;
  			}
  		};
  		http.send(post_parameters);
  		return true;
  	}
  	else
  	{
  		console.log("no ajax..  sorry.");
  		return false;
  	}
  }

    var http = new XMLHttpRequest();
    if (http != undefined) {
        ...
    }

    var ajaxObject;
    if (window.XMLHttpRequest) {
      ...
    } else if (window.ActiveXObject) {
      ...
    }
    
    if (ajaxObject) {
      ...
    } else {
      //handle users without ajax
    }

    $.ajax();

So you're comparing the body of one function to the signature of another? I know I posted some really shitty code, but you managed to shoot yourself in the foot even in that scenario, grats.

https://github.com/jquery/jquery/blob/master/src/ajax.js

Here, now it's apples to apples.

That said, I have nothing against jQuery, but what used to annoy me was seeing Javascript questions being answered with jQuery snippets without anyone blinking, everywhere and all the time... you see, that's actually coming onto "my" turf and wantonly murdering there. That was too much, and if a "backlash" is needed to restore some sanity and balance, I say lash away.