Recs.
Updated
SpecsUpdate
Pros
Pro Great full featured support for Markdown preview (using Markdown-Preview-Enhanced)
Most feature rich markdown preview among editors, you can import PDF right inside document, using @import
you can run python, it's like having IPython/Jupyter support, full math support, full LaTeX (even entire document) support. Tikz, Viz, GnuPlot, UML, etc.
Pro Easy access to lots of packages that extend functionality
Atom has a built-in package manager and an extensive list of packages. There are over 150 markdown related packages available for Atom. Additionally, packages are written in CoffeeScript so anyone that knows CoffeeScript can write packages for Atom to extend functionality.
Pro Extensive list of packages
Atom has a built-in package manager and an extensive list of packages. Packages are written in CoffeeScript.
Pro Great mixed RTL/LTR implementation
Correctly displays mixed RTL(right-to-left)/LTR(left-to-right) within the same document.
Cons
Con Installation is very hard for new users who only want a decent markdown editor
Frustratingly difficult to figure out how to use as a markdown editor. Search on Web and nothing. It's obvious it's some sort of universal scripting editor and you have to install packages to get it to do anything. Once configured properly it will work but there's no information on what packages to install, how it works or how to use it.
Con Slow
Atom is not a native application. As such performance is subpar and the lag is especially noticeable on larger projects. It also opens a surprising amount of sub-processes and leaks a considerable amount of memory.
Recommendations
Comments
Flagged Pros + Cons
Pro Powerful command palette
The Command Palette allows fuzzy searching all available functions, settings, snippets, etc.
Pro Live split-screen preview
Markdown preview can be accessed by going Packages > Markdown > Toggle Preview.
Pro Easy access to lots of packages that extend functionality
Atom has a built-in package manager and an extensive list of packages. There are over 150 markdown related packages available for Atom. Additionally, packages are written in CoffeeScript so anyone that knows CoffeeScript can write packages for Atom to extend functionality.