When comparing Emacs vs StackEdit, the Slant community recommends StackEdit for most people. In the question“What are the best Markdown editors for OS X?” StackEdit is ranked 1st while Emacs is ranked 13th. The most important reason people chose StackEdit is:
StackEdit works within your browser. You need internet access to connect to the website, but once it's loaded, the site does not require an internet connection - you will be able to edit and save files locally. Additionally, you can use [Fluid](http://fluidapp.com) to turn it into a native desktop application.
Ranked in these QuestionsQuestion Ranking
Pro Keyboard-focused, mouse-free editing
Emacs can be controlled entirely with the keyboard.
Pro Total customizability
Customizations can be made to a wide range of Emacs' functions through a Lisp dialect (Emacs Lisp). A robust list of existing Lisp extensions include the practical (git integration, syntax highlighting, etc) to the utilitarian (calculators, calendars) to the sublime (chess, Eliza).
Pro It's also an IDE
You can debug, compile, manage files, integrate with version control systems, etc. All through the various plugins that can be installed.
Pro Works in terminal or as a GUI application
You can use Emacs' command line interface or graphical user interface.
Pro Self documenting
Emacs has extensive help support built-in as well as a tutorial accessed with C-h t.
Licensed under GNU GPL.
Pro Great documentation
With 30+ years of use the Emacs documentation is very thorough. There are also a lot of tutorials and guides written by third parties.
Pro Mini buffer
You can pass complicated arguments in the mini buffer.
Fully compliant GNU-emacs is available on many platforms, and they all understand .emacs configuration files.
Pro Rectangular cut and paste
Emacs can select rectangularly.
Pro Lisp customizations
With lisp customization, any behavior of Emacs can be changed. Update with pre-release patch can be also applied without recompiling the whole Emacs.
Pro Vi keybindings through Evil mode
Evil mode emulates vim behaviors within Emacs. It enables Vi users to move inside the Emacs universe.
Pro Visual selection and text objects with Evil
Evil is an extensible vi layer for Emacs. It provides Vim features like Visual selection and text objects.
Pro Support multi-line editing, multiple frame, powerful paren, crazy jumping style
Review the "Emacs Rocks" video.
Pro Provides org-mode
Advanced planning and publication which can start as a simple list.
Pro Has been widely used for a long time
Pro dabbrev-expand (Alt-/)
Dynamic word completion.
Works on Linux, Windows, Macintosh, BSD, and others.
Pro Enormous range of functionalities (way beyond simple "text editing")
Through its programmability, a very broad range of functionalities can be integrated in emacs, turning it even into a "single point of contact" with the underlying operating system.
Pro Integrates planning in your development process
You can jump straight from your org-mode files to programming tasks - and back - and build a seamless workflow.
Pro Helm plugin adds even more power to Emacs
Powerful commands, search, and more with the Helm plugin.
Pro GTK+ widgets support
Pro Works online and offline
StackEdit works within your browser. You need internet access to connect to the website, but once it's loaded, the site does not require an internet connection - you will be able to edit and save files locally. Additionally, you can use Fluid to turn it into a native desktop application.
Pro No need to install additional software
StackEdit works directly from the browser, there's no need to install additional software as long as you have a web browser installed on your computer.
Pro Real-time preview
The preview shows in a collapsible pane on the right hand side.
Pro Multiple export options
Can export to .txt, .html and .pdf.
Pro Great when in full-screen
Pro Supports various Markdown flavors
Supports standard Markdown and Markdown Extra.
Pro Instant publishing
StackEdit allows pushing a document directly to a list of publishing or file storage platforms or any SSH server.
Pro Syncs via Dropbox and Drive
Files can be synchronized through Dropbox and Drive.
Pro Simple workflow
It is very easy to toggle between the preview and the editing windows. The black makes it a very focused writing environment. Of course it's possible to change that if needed.
Con Learning curve is long
While it's better than it used to be, with most functions being possible through the menu, Emacs is still quite a bit different from your standard editor. You'll need to learn new keyboard shortcuts.
Con Sometimes the extensibility can distract you from your actual work
If I ever want to lose half a day, I'll start by tweaking my .spacemacs config file.
Con Chorded keyboard combinations can be baffling
For example, for navigation it uses the b, n, p, l keys. Which for some people may seem strange. But don't worry, you can change it.
Con A lot of jokes in this serious software
Con Using Emacs on a new machine without your .emacs file
Con Cannot be accessed while being offline
Even though the editor itself works offline, you need internet access to open the website and the editor.
Con Saves files in browser's local storage
Local storage is limited and if the browser crashes the text can be lost.
Con Publishing to GitHub requires giving write access to repos
In order to publish documents to GitHub, StackEdit requires writing access to your repos, something which many people may not be comfortable with.
Con Lacks a good integrated spell checker
Uses the built-in browser spell checker which may not be as good as spell checkers other editors have. Depending on the browser, of course.