If you want to use Emacs on your home PC running Microsoft Windows, you can download it for free. Simply fetch the file with a name like emacs-25.1-2-i686-w64-mingw32.zip (the version number may change). Unzip the zip file preserving the directory structure, and run binrunemacs.exe. Alternatively, create a desktop shortcut to binrunemacs.exe, and start Emacs by double-clicking on that shortcut's icon.
Macintosh users may want to explore Aquamacs Emacs, which is Mac version of emacs that feels and behaves mostly like a 'standard' Macintosh application. In addition, there's a version emacs that is included with Mac OS X. This version is not aware of X-windows; however, the version that is available via Finkis X-windows aware.
Emacs For Mac Terminal
Emacs is back with a vengeance. I recently got a new MacBook and have developed the need for some native Emacs goodness. I looked around (though not too hard) and didn't see any other Emacs binaries except for Aquamacs, but it is too divergent from normal Emacs behavior for me. On top of the versatile Emacs text processing tools, Aquamacs Emacs offers you the possibility to see each document in a separate window, provides support for using tabs in your document, can work.