NERDTree is on the lookout for a new maintainer. See issue #1280 to submit your name for consideration.

The NERDTree is a file system explorer for the Vim editor. Using this plugin, users can visually browse complex directory hierarchies, quickly open files for reading or editing, and perform basic file system operations.

Use your favorite plugin manager to install this plugin. tpope/vim-pathogen, VundleVim/Vundle.vim, junegunn/vim-plug, and Shougo/dein.vim are some of the more popular ones. A lengthy discussion of these and other managers can be found on vi.stackexchange.com. Basic instructions are provided below, but please be sure to read, understand, and follow all the safety rules that come with your power tools plugin manager.

If you have no favorite, or want to manage your plugins without 3rd-party dependencies, consider using Vim 8+ packages, as described in Greg Hurrell's excellent Youtube video: Vim screencast #75: Plugin managers.

call plug#begin()
  Plug 'preservim/nerdtree'
call plug#end()

git clone https://github.com/preservim/nerdtree.git ~/.vim/pack/vendor/start/nerdtree
vim -u NONE -c "helptags ~/.vim/pack/vendor/start/nerdtree/doc" -c q

After installing NERDTree, the best way to learn it is to turn on the Quick Help. Open NERDTree with the :NERDTree command, and press ? to turn on the Quick Help, which will show you all the mappings and commands available in the NERDTree. Of course, your most complete source of information is the documentation: :help NERDTree.

NERDTree can be extended with custom mappings and functions using its built-in API. The details of this API are described in the included documentation. Several plugins have been written, and are available on Github for installation like any other plugin. The plugins in this list are maintained (or not) by their respective owners, and certain combinations may be incompatible.

• Xuyuanp/nerdtree-git-plugin: Shows Git status flags for files and folders in NERDTree.
• ryanoasis/vim-devicons: Adds filetype-specific icons to NERDTree files and folders,
• tiagofumo/vim-nerdtree-syntax-highlight: Adds syntax highlighting to NERDTree based on filetype.
• scrooloose/nerdtree-project-plugin: Saves and restores the state of the NERDTree between sessions.
• PhilRunninger/nerdtree-buffer-ops: 1) Highlights open files in a different color. 2) Closes a buffer directly from NERDTree.
• PhilRunninger/nerdtree-visual-selection: Enables NERDTree to open, delete, move, or copy multiple Visually-selected files at once.

If any others should be listed, mention them in an issue or pull request.

In the answers to these questions, you will see code blocks that you can put in your vimrc file.

NERDTree doesn't create any shortcuts outside of the NERDTree window, so as not to overwrite any of your other shortcuts. Use the nnoremap command in your vimrc. You, of course, have many keys and NERDTree commands to choose from. Here are but a few examples.

nnoremap <leader>n :NERDTreeFocus<CR>
nnoremap <C-n> :NERDTree<CR>
nnoremap <C-t> :NERDTreeToggle<CR>
nnoremap <C-f> :NERDTreeFind<CR>

Each code block below is slightly different, as described in the " Comment lines.

" Start NERDTree and leave the cursor in it.
autocmd VimEnter * NERDTree

" Start NERDTree and put the cursor back in the other window.
autocmd VimEnter * NERDTree | wincmd p

" Start NERDTree when Vim is started without file arguments.
autocmd StdinReadPre * let s:std_in=1
autocmd VimEnter * if argc() == 0 && !exists('s:std_in') | NERDTree | endif

" Start NERDTree. If a file is specified, move the cursor to its window.
autocmd StdinReadPre * let s:std_in=1
autocmd VimEnter * NERDTree | if argc() > 0 || exists("s:std_in") | wincmd p | endif

" Start NERDTree, unless a file or session is specified, eg. vim -S session_file.vim.
autocmd StdinReadPre * let s:std_in=1
autocmd VimEnter * if argc() == 0 && !exists('s:std_in') && v:this_session == '' | NERDTree | endif

" Start NERDTree when Vim starts with a directory argument.
autocmd StdinReadPre * let s:std_in=1
autocmd VimEnter * if argc() == 1 && isdirectory(argv()[0]) && !exists('s:std_in') |
    \ execute 'NERDTree' argv()[0] | wincmd p | enew | execute 'cd '.argv()[0] | endif

" Exit Vim if NERDTree is the only window remaining in the only tab.
autocmd BufEnter * if tabpagenr('$') == 1 && winnr('$') == 1 && exists('b:NERDTree') && b:NERDTree.isTabTree() | quit | endif

" Close the tab if NERDTree is the only window remaining in it.
autocmd BufEnter * if winnr('$') == 1 && exists('b:NERDTree') && b:NERDTree.isTabTree() | quit | endif

" If another buffer tries to replace NERDTree, put it in the other window, and bring back NERDTree.
autocmd BufEnter * if winnr() == winnr('h') && bufname('#') =~ 'NERD_tree_\d\+' && bufname('%') !~ 'NERD_tree_\d\+' && winnr('$') > 1 |
    \ let buf=bufnr() | buffer# | execute "normal! \<C-W>w" | execute 'buffer'.buf | endif

" Open the existing NERDTree on each new tab.
autocmd BufWinEnter * if &buftype != 'quickfix' && getcmdwintype() == '' | silent NERDTreeMirror | endif

or change your NERDTree-launching shortcut key like so:

" Mirror the NERDTree before showing it. This makes it the same on all tabs.
nnoremap <C-n> :NERDTreeMirror<CR>:NERDTreeFocus<CR>

let g:NERDTreeDirArrowExpandable = '?'
let g:NERDTreeDirArrowCollapsible = '?'

The preceding values are the non-Windows default arrow symbols. Setting these variables to empty strings will remove the arrows completely and shift the entire tree two character positions to the left. See :h NERDTreeDirArrowExpandable for more details.

Short answer: No, and there are no plans to add that functionality. However, Vim ships with a plugin that does just that. It's called netrw, and by adding the following lines to your .vimrc, you can use it to open files over the scp:, ftp:, or other protocols, while still using NERDTree for all local files. The function seamlessly makes the decision to open NERDTree or netrw, and other supported protocols can be added to the regular expression.

" Function to open the file or NERDTree or netrw.
"   Returns: 1 if either file explorer was opened; otherwise, 0.
function! s:OpenFileOrExplorer(...)
    if a:0 == 0 || a:1 == ''
        NERDTree
    elseif filereadable(a:1)
        execute 'edit '.a:1
        return 0
    elseif a:1 =~? '^\(scp\|ftp\)://' " Add other protocols as needed.
        execute 'Vexplore '.a:1
    elseif isdirectory(a:1)
        execute 'NERDTree '.a:1
    endif
    return 1
endfunction

" Auto commands to handle OS commandline arguments
autocmd StdinReadPre * let s:std_in=1
autocmd VimEnter * if argc()==1 && !exists('s:std_in') | if <SID>OpenFileOrExplorer(argv()[0]) | wincmd p | enew | wincmd p | endif | endif

" Command to call the OpenFileOrExplorer function.
command! -n=? -complete=file -bar Edit :call <SID>OpenFileOrExplorer('<args>')

" Command-mode abbreviation to replace the :edit Vim command.
cnoreabbrev e Edit