I started using Emacs about 1990 but have been using it exclusively for just two years. Prior to that my main editor was TSE Pro – a fast, customizable Windows-only editor that evolved from a 1980s DOS editor called Qedit. The motivation for switching to Emacs was that I wanted to be able to work in the same way on both Windows and Mac machines. After looking at the possibilities I settled on Emacs as the ideal solution.
Although Emacs dates from the 1980s, it seems to have enjoyed renewed popularity in the last few years, with regular new releases (currently version 24.3), many new packages appearing, several excellent Emacs blogs posting regularly, and even an Emacs conference held in London in March 2013.
For me the main advantages of Emacs are
- Excellent LaTeX integration through AucTeX and RefTeX.
- ORG mode, an incredibly powerful mode for working with plain text. Among its uses are
- making notes and outlines,
- TODO lists,
- writing documents in a simple markup language that can be exported to LaTeX, html, and various other formats,
- writing and managing WordPress blogs, via org2blog (this blog is produced entirely from within Emacs, apart from some tweaking in WordPress).
In all these cases, the ability to narrow the view to certain parts of the buffer, and to reorder logical units via simple keypresses, provide tremendous usability.
- Complete built-in documentation, with the ability to see the Emacs Lisp source code for all functions except the small number of low-level functions written in compiled C.
- The ability to customize every aspect of Emacs, and in particular to reassign almost any keypress.
- The use of Emacs is essentially system-independent; in particular Emacs has its own file management functions, which bypass the Windows, Mac or Linux file open/save dialog boxes.
I’ll write about some of these aspects in future posts.
For now, here are some videos that provide more information:
- 5-minute intro to Emacs
- Emacs Rocks episodes: inspirational 3-minute videos from Magnar Sveen, who also writes the What the .emacs.d blog.
- Emacs screencasts: a list hosted at the EmacsWiki.
And for an excellent perspective on the eternal “Emacs/Vi versus the latest hot editor” debate I recommend the post Good tools by James Bennett, which appeared just as I was about to publish this post.
Nick Higham 
Good to hear about the renewed interest in Emacs. I still encounter an attitude of skepticism, along the lines of “You’re still using a text-based tool?” when I mention that I use Emacs.
However, at this point, my muscle-memory is so engrained that I resist learning a new editor every time I want to try out a new programming language. Also, I don’t see the point of spending time to become acquainted with an environment that frequently has less functionality.
It’s also good to hear what other people like about Emacs as it encompasses so much, I feel I’m barely acquainted with it after twenty-some years of using it.