console.log is now a standard used by not only Firebug, but WebKit Inspector and Internet Explorer Developer Tools. Firebug is ubiquitous with front end web development, and while it provides dozens of tools like DOM inspection and network sniffing, the logger gets the vast majority of use.
log, warn, and info may be standard, using the
groupCollapsed method will throw an error in Chrome, and the seemingly innocuous
debug will throw an error in IE. Opera’s Dragonfly is an improvement over it’s anemic predecessor, but it still rivals IE’s feeble text-only logger and thus, only supports a small subset of console methods.