If you're learning something, about the only thing you really want is syntax highlighting. Go beyond that and you run the risk of "throwing out the baby with the bathwater."
That would be more like throwing into
the tub: the baby, the bathwater, some soap, some rubber duckies, a teddy bear and a LEGO set
That said, I disagree - just a little. Syntax highlighting is very helpful for spotting syntax errors, which abound when you begin learning a language. But for me, the lack of IDE (or using a weak IDE) becomes a showstopper for another reason: no code insight. For me, the hardest thing is figuring out what I can do with the language, i.e. the capabilities of the library.
A few times I've tried learning Python by attempting to write what should normally be much simpler/faster to do in Python than in Delphi. Of course, while I knew exactly how to do it in Delphi, but in Pyton I had no idea where to begin. Every time, with only one exception, I went back to Delphi, having to write more glue code and create throw-away classes, but I worked fast because I already knew how to do it. In Python, without an IDE capable of code insight, searching in the documentation ended up taking enough time to become a tedium.
If I can type objectinstance - dot - Ctrl+Space and have a list of methods and their signatures, I'm happy, and I can try things out in no time and actually get results. Without it, a new language appears impenetrable.
That, and I don't think I'd ever attempt to create a GUI in a scripting language by typing... control such-and-such, top=10, left=5, width=100, etc, for dozens and dozens of controls. It just doesn't seem to make sense, as long as you have an option of using a visual designer.