spacemacs

dotspacemacs-configuration-layers
   '(
     ;;pdf-tools
     ;;eww
     xkcd
     markdown
     themes-megapack
     tmux
     elixir
     ;; ----------------------------------------------------------------
     ;; Example of useful layers you may want to use right away.
     ;; Uncomment some layer names and press <SPC f e R> (Vim style) or
     ;; <M-m f e R> (Emacs style) to install them.
     ;; ----------------------------------------------------------------
     helm
     ;; auto-completion
     ;; better-defaults
     emacs-lisp
     git
     ;; markdown
     org
     ;; (shell :variables
     ;;        shell-default-height 30
     ;;        shell-default-position 'bottom)
     ;; spell-checking
     ;; syntax-checking
     ;; version-control
     )