It is often said that there is almost no good IDEs in Unix. I finally realised that this is wrong. There is one very good IDE called Emacs. It does not look like IDE simply because it uses very powerful mechanism of commands and keyboard shortcuts instead of fancy menus, buttons and stupid dialogs usually found in other IDEs. But other than that, Emacs is full-featured IDE which supports a lot of languages and at least compiling, debugging, navigation and completion. Compared to Borland IDEs, Emacs is a way better. Compared with things like Eclipse and IntelliJ IDEA it lacks only GUI builder and refactoring tools. Former is not a problem because there is a lot of very good GUI builders that can be used independently of editor (like Qt Designer), the latter is a little bit disappointing, though. Maybe I did not search well enough or maybe refactoring is not really needed with true Unix development style (this makes sense, since I did not miss refactoring even once).
Nonetheless, Emacs is really an IDE. If it seems strange to you, imagine that your favorite IDE has all its menus, toolbars and panels removed, their functions bound to key sequences (less often used ones to text commands), and you will quickly understand why Emacs looks like an editor.
So, to continue "Emacs and Vim" discussion, it becomes very simple: Vim is the best editor, Emacs is the best IDE.