Consider Emacs: it is extremely muaoldr and extremely extensible by virtue of it’s embedded Lisp interpreter. This is a strange thing to say in a paragraph talking about the Unix Philosophy, since Emacs comes from a completely different culture (MIT/ITS/Lisp vs Bell/PDP/C) and is virtually the antithesis of the Unix Way (everything in one process, communicating by function calls with rich data types).I love Emacs as much as anybody, but I wouldn't claim it has anything to do with Unix. We even had a funny name for the Unix port of Emacs ( Gosmacs ) way back when that wasn't the common place to run it!P: Have you ever tried building a medium-large-scale application (say, a project with 50-60 classes) with emacs and gcc? I’m sure it’s possible, with persistence Yes, I'm working on a large system right now not in C, but it has over 600 classes, and I don't know what an IDE could do for me that Emacs can't. find-tag is just as fast with 600 classes as with 6. Macros make O(n) editing tasks into O(1) editing tasks on any size project.What specific feature of an IDE helps you here? Everything I can think of that IDEs brag about, I do in Emacs every day.