Is it worth investing time in learning to use Emacs?

[Disclaimer: personally, I prefer Vim. Disclaimer disclaimer: read on.]

Vim excels in the small: by making motion and action separate concepts and providing facilities for complex repeats, you can perform incredibly powerful editing operations in just a short sequence of keystrokes. You can easily do things in Vim in the normal course of editing that would require you to drop down to scripting in Emacs. Also, most of the power you use comes out of the box, so even if you have extensive .vimrc customisations, chances are you will be able to work productively with any Vim installation.

Emacs excels in the large: by mapping all of its UI concepts directly to basic constructs and concepts in Elisp, it becomes very easy to globally introduce features for specific kinds of files or circumstances, making Emacs something like a text-based and much more structuredly programmable form of Excel. This presumes that you are going to spend a lot of time customising your environment for personal needs and preferences. Of course, Emacs does do its best to make it easy to stay inside that one environment for everything and anything you may want to do.

Ultimately, neither is superior. They offer different styles, and depending on your proclivities, one or the other will suit your personal needs and way of thinking better. It is always helpful to know both (plus more editors), of course. But you aren’t going to be appreciably more productive this way or that.

I prefer emacs to vi, but I'm comfortable in both.

There are some things that you can do in emacs that make it more powerful than vi, but not all of them are even programming-related. (Can you send email or read news from within vi? No, but who cares?) If you're comfortable with lisp (I'm not), you might be able to write add-ons and modes and stuff to make your life easier, but that's just likely to be syntax colouring and brace matching and eye candy like that.

I will stop rambling now. Will your productivity increase using emacs? No.

Update: See my comment below. Since I posted this, I have come across ways that using emacs has made me more productive than using vi.

vi is a kitchen knife.

vim is a really nice, sharp, balanced chef's knife.

Emacs is a light saber.

Most of the time, my job requires me to chop vegetables. Occasionally, I have to take on an entire army of robots.

I've been using Emacs for 20 years. I'm typing in Emacs right now with a widget called "It's All Text" that lets me suck text in and out of text boxes in Firefox. I can go really fast in Emacs. I am significantly less productive without it.

This is highly debateable, but I also think that learning Emacs can teach you a surprising amount about programming.

Depending on how you code, you may see a productivity increase. For background, I'm also a long-time vim user, but I learned emacs about 2 years ago, and now use them interchangeably.

What drove me to the point of actually learning emacs was its useful ability to have a large number of files open at once, and to easily switch between them. I was in the middle of introducing a feature that added and touched a large number of classes. (This was C++, so there were typically two files per class.) Since I was still firming up the interface, I would typically be in the middle of updating one file when I would realize that I needed to change another.

With gvim, it was easiest to open a new window for each file, which was starting to get unwieldy. With Emacs, though, it was simple to open a new file in the same window (Ctrl-x, Ctrl-f). Once Emacs has a file open, it's very easy to switch back and forth between the open buffers (Ctrl-x, Ctrl-b).

Taking that one step further, a single emacs session may open many windows, so in addition to splitting the window vertically, I could decide, without interrupting work on a file, to open another next to it, letting me effectively work side-by-side while still keeping each window at the default 80-character width.

There are still some things that I find easier in vim (e.g. block-select mode, simple macro recording, diff mode), and things that are easier in Emacs (line alignment, file/buffer management, window/screen management). Therefore, I find myself alternating between the two (and sometimes using both simultaneously), depending the editing task I anticipate.

If you're still unsure, I'd suggest trying it out. Run through the Emacs tutorial and then use it to write code for a morning or a day, leaning heavily on the help. If you still don't like what you see, stay with vim. Regardless of what the editor brings to the table, your familiarity and knowledge of the tool will by far be the most important factor in your productivity.