Download Emacs for Windows/Mac
Windows
Download at http://ftp.gnu.org/pub/gnu/emacs/windows/
This is the official GNU Emacs, build for Windows by Free Software Foundation.
You'll see file names like these:
- emacs-27.1-i686.zip → for 32 bits machine
- emacs-27.1-x86_64.zip → for 64 bits machine

To find if your Microsoft Windows is 32 or 64, press ❖ Window key, type “about” in the search box. It'll bring up “About” window. Look for the line “system type”.

After download, right click on the zip file, select “extract all” to unzip it.
Then open the extracted folder, open the folder named “bin”, click the “runemacs” to start emacs.

To uninstall, just delete the folder.
Mac
In terminal, type:
which emacs
- check if emacs is installed and in your path.
emacs --version
- print version.
emacs
- launch emacs. (to quit, press Ctrl+x Ctrl+c)
Download Latest Emacs for MacOS
- Download plain GNU Emacs, built by David Caldwell. At http://emacsformacosx.com/
- Homebrew http://brew.sh/
- MacPorts https://www.macports.org/
you can double click the icon to launch emacs.
or, launch emacs in terminal, like this:

see also Emacs on MacOS Cannot Access File
Linux
Build Emacs from Source Code
Download Emacs Binary from apt-get
In terminal, type:
which emacs
- check if emacs is installed and in your path.
emacs --version
- print version.
emacs
- launch emacs. (to quit, press Ctrl+x Ctrl+c)
On Ubuntu, to check available emacs package version for install,
# search for emacs binary apt-cache search emacs | grep emacs
Typically you install by
sudo apt-get install emacs27
, where the emacs27 may be other version.
Android Operating System

Download termux https://termux.com/ from f-droid at https://f-droid.org/en/packages/com.termux/