All modern browsers (with one exception we'll get to later) have a debugging console built into the browser to assist you in debugging your JavaScript. All of the debuggers provide basically the same options once you have it open. The biggest differences are how you access the debugger in the first place and what the debugger looks like once you have it open.
We'll look at how to open the debugging console from each of the different browsers and then at what the debugging console looks like in that browser. In the case of Firefox (the one browser that doesn't have a debugging console built in), we'll first look at where to download the Venkmann debugging console extension so that you can install the same debugging functionality into that browser as the other four have built in.