Firebug and firebug lite were amazing but to keep the record clear it was possible to debug client-side JavaScript (and other script types) using Visual Studio since very early on in IE. It was granted a major pain to setup properly for breakpoints and code highlighting but it was a full fledged debugger and IDE. I remember doing it often. I don’t remember if there was a debugger for IE for mac and early Safari. For me those where where “alert” and “document.write” were my only options.

I had forgotten about those days. The VS debugger slowed down my computer so much though that I often just used alert anyway. Firebug was a huge improvement.

Lol I remember that little yellow triangle. The source of so much pain.

undefined is not a function

So true, debugging with alert()…

There was Firebug Light, which from memory was a bookmarklet that injected a cut down firebug into the page, but even that didn’t help much.

Not owning any Apple products myself, my only option was a free online emulator to try and fix a bug on older iOS systems. It did not support console logs, so I was trying to debug using alert() as far back as yesterday. It didn't help, I only managed to find the issue through xCode on a random Mac.