I very reluctantly conceded this point a few years ago, but in a slightly different way. I've been doing JavaScript-as-a-kludge-for-whatever-server-side-framework-I-happen-to-discover-the-limitations-of for a while. I'm discovering that the complexity of every browser's quirks means I'm going to have to do more than just "learn it". And therein lies the problem.

JavaScript isn't an awful language (all languages have their pluses and minuses and developers are so touchy on this subject, I don't even want to broach it). It's the sheer number of platforms (browser/hardware/OS combinations) that make JavaScript painful to learn properly. Every browser on every device must perform adequately. It's not a matter of supporting Windows or MacOS, it's every variant of RIM device, i* device, every browser on Windows Mobile taking into account the performance/memory footprint (to a lesser extent anymore), and devices with browser variants running on Android.

For the sake of my current set of projects -- requiring reasonable compatibility across platforms, but not a universally good user experience on all, learning jQuery became a necessity. Though I'd prefer to not be framework dependent, I've found that understanding how to use jQuery has also improved my understanding of the various quirky implementations of JavaScript in general.

I have no doubt that future projects will require a good user experience on most platforms. Does anyone have any suggestions regarding good, comprehensive resources in this area? The blog post mentions several online resources for folks wishing to learn/understand the language (some of which I haven't used before), but I'm wondering if there are particularly excellent tools beyond that (IDEs, good debuggers beyond Firebug) or anything else out there that can assist in identifying code that won't work, or won't work well in cross platform scenarios (for free or not).