Different browsers, same API.
Both Firebug and Web Inspector have console API support. Opera and IE 8–9 kind of have it. IE≤7 doesn't have it at all.
Console.js — crossbrowser Firebug console API
>>> console.log({x:3, y:5})
{x: 3, y: 5}
>>> console.dir({x:3, y:5})
{
x: 3,
y: 5
}
>>> console.log(document.body)
<BODY class="timeline" id="home">
>>> console.dir(document.body)
HTMLBodyElement {
aLink: "",
attributes: NamedNodeMap {
0: Attr {?}
...
}
}