I think there is still a load of room for improvement in the way text editors convey information. IDEs have improved rapidly at leveraging syntax highlighting, marking error occurrences, code folding to hide unimportant stuff, indicating whether a method is overriding another method, displaying diffs against an SCM, etc. But those are visual editor improvements, not changes in the code itself. I distrust any part of my program that doesn’t exist somewhere as text in a file.

The benefit of text is that it is precise. Writing code is necessarily an exercise in precision given the target (computer) is kind of a stickler for it. Our visual systems are phenomenal but they are not designed for the kind of precision a language demands.

Consider software architecture. Is it easier to get a high level overview of a component using a UML diagram or looking at source code?

Text is a new phenomenon. Vision is an old one. We have fairly well developed vision because we were at one time hunters. Humans can easily discern between two colors. Or look at three objects and tell which one is bigger. Humans are very bad at looking at two instances of “.x = 486″ and one of “.x = 490″ and realizing that the width of two boxes is different.

To harness the power of our biology I would recommend using colors, shapes, and size to communicate information. I really like those widgets that do a frequency count of keywords and then render the common words in a bigger font. (UserScripts.org used to do this… don’t know the name of the technique). That was a communication medium that harnessed our biology! Very cool.

I too think we’ll use text editors for a long time… but I think the cause is developer’s lacking imagination rather than a test editor’s fitness of purpose.

On #3, I consider XML-based languages to be DSLs, but then I’m willing to take a pretty wide interpretation of the term. However, I think most XML-based DSLs are fairly bad as DSLs due to their verbosity. I think either external DSLs built with tool support from language tools or embedded DSLs in general-purpose languages that have good support for them are much better options.