This page is a guide on which emacs to download for {Windows, Mac, Linux}.
This is the official GNU Emacs, build for Windows by FSF.
Download: http://ftp.gnu.org/pub/gnu/emacs/windows/
You want to download the one named like this: “emacs-24.2-bin-i386.zip”.
Just download, unzip, and use right there. No installation step needed.
To un-install, just delete the folder.
This is a emacs distro created by Lennart Borgman. It is a emacs with Windows specific patches, with some extra elisp packages bundled.
Main feature includes the ability to use the Alt key to invoke menu like other Windows apps; set ❖ Win key as Meta; use OS-wide Sticky Keys from Windows's “Ease of Access Center”, fixes such as to make printing easier, makes emacs ftp work, bundled nXhtml mode for working with mixed HTML/CSS/Javascript code, …
Download: http://www.ourcomments.org/Emacs/EmacsW32.html.
You want to download the one named “EmacsW32 + binaries for Emacs”. Then, run the installer.
To un-install, run the un-installer.
ErgoEmacs is a distro created by Xah Lee (me) and David Capello.
Main feature includes a ergonomic based emacs keyboard shortcut set, fixes so that many emacs features work in Windows, bundles the whole unix command tool utilities (grep, find, diff, patch… from MinGW), and bundles many Windows specific language modes. For detail, see: ErgoEmacs Features.
Download: ErgoEmacs.org.
Download and run the installer.
To un-install, run the un-installer.
Download: Source emacsformacosx.com. This is plain GNU Emacs, built by David Caldwell.
Aquamacs Emacs is a emacs with complete Mac user interface, by David Reitter.
Aquamacs's interface is similar to BBEdit or TextMate or in fact any modern Mac software. It uses the same keyboard shortcuts Mac users are familiar. Also uses tabs, multiple windows, pop up dialogs, Apple's help documentation system, etc., and bundles many extra packages, in particular LaTeX support.
If you never used emacs before, or never used a text terminal or unix, this is a great choice.
Download: http://aquamacs.org/.
On Ubuntu, typically you install by sudo apt-get install emacs24, where the emacs24 may be other version. To find out what's the package name, do: apt-cache search emacs | grep emacs.
Source code at http://ftp.gnu.org/gnu/emacs/
For latest emacs release, it may not be bundled by the OS yet. You'll need to build it yourself. See: Building Emacs on Linux, a Guide.
Personally, i use ErgoEmacs on top of a default GNU emacs, on any OS.