The classic "Unix is many small tools and Emacs is one big tool" argument is well known, but rarely substantiated. Emacs tools are not any more tightly coupled

The classic "Unix is many small tools and Emacs is one big tool" argument is well known, but rarely substantiated. Emacs tools are not any more tightly coupled because they're written in Emacs Lisp than your tools are because they're written in C. In fact, just as all your tools run in a terminal, all my Emacs tools run in buffers (in Emacs). Speaking loosely, Emacs is the embodiment of Unix: it has many tools written by the community, some of which are installed by default, and you can choose which you want to run that best suit your needs. "Integration" doesn't really fit into the picture. For example, Emacs has both ERC and rcirc. I use ERC, but my point is that there are choices. Emacs has several mail readers (Wanderlust, GNUs, mew, etc) and several terminal emulators. Eshell provides one type of feel, treating your shell as a buffer. Term provides a more classic terminal emulator feel, when you don't want to treat your term like a text editing session. As to your "! is text in, text out", try M-! in Emacs. I daresay Emacs has fairly robust system integration as well. I have run irssi from term buffers for fun. Even more ironic is running vi in a term buffer. In short, it may be more useful for you to think of Emacs as a replacement for your terminal emulator than as a replacement for vi.