diff --git a/autoload/vital/_popup.vim b/autoload/vital/_popup.vim
new file mode 100644
index 000000000..55104952e
--- /dev/null
+++ b/autoload/vital/_popup.vim
@@ -0,0 +1,9 @@
+let s:_plugin_name = expand('<sfile>:t:r')
+
+function! vital#{s:_plugin_name}#new() abort
+  return vital#{s:_plugin_name[1:]}#new()
+endfunction
+
+function! vital#{s:_plugin_name}#function(funcname) abort
+  silent! return function(a:funcname)
+endfunction
diff --git a/autoload/vital/_popup/Experimental/UI/Popup.vim b/autoload/vital/_popup/Experimental/UI/Popup.vim
new file mode 100644
index 000000000..3d0bfa834
--- /dev/null
+++ b/autoload/vital/_popup/Experimental/UI/Popup.vim
@@ -0,0 +1,225 @@
+" ___vital___
+" NOTE: lines between '" ___vital___' is generated by :Vitalize.
+" Do not modify the code nor insert new lines before '" ___vital___'
+function! s:_SID() abort
+  return matchstr(expand('<sfile>'), '<SNR>\zs\d\+\ze__SID$')
+endfunction
+execute join(['function! vital#_popup#Experimental#UI#Popup#import() abort', printf("return map({'options': '', 'bufnr': '', 'hide': '', 'create': '', 'show': '', 'is_supported': '', 'close': '', 'winid': '', 'contents': ''}, \"vital#_popup#function('<SNR>%s_' . v:key)\")", s:_SID()), 'endfunction'], "\n")
+delfunction s:_SID
+" ___vital___
+let s:save_cpo = &cpo
+set cpo&vim
+
+let s:_has_nvim = has('nvim')
+let s:_popups = {}
+let s:_id = 0
+
+function! s:is_supported() abort
+  return has('nvim') && exists('*nvim_open_win') || (!has('nvim') && exists('*popup_create') && has('patch-8.2.0286'))
+endfunction
+
+" opt = {
+"   'contents': ['This', 'is', 'a', 'line'],
+"   'w': 5,
+"   'h': 5,
+"   'x': 1,
+"   'y': 1,
+"   'pos': 'topleft|topright|bottomleft|bottomright|topcenter|bottomcenter',
+" }
+function! s:create(opt) abort
+  let id = s:_nextid()
+  let data = { 'winid': 0 }
+
+  call s:_set(data, a:opt)
+
+  if s:_has_nvim
+    let data['bufnr'] = nvim_create_buf(0, 1)
+    call nvim_buf_set_lines(data['bufnr'], 0, -1, 1, data['contents'])
+    let data['winid'] = s:_nvim_open_win(data)
+  else
+    " neovim doesn't support scrollbar so don't enable it
+    let data['winid'] = popup_create(data['contents'], s:_get_vim_options(data))
+    let data['bufnr'] = winbufnr(data['winid'])
+  endif
+  let s:_popups[id] = data
+  call s:_notify(id, {}, 'create')
+  call s:_notify(id, {}, 'show')
+  return id
+endfunction
+
+function! s:close(id) abort
+  let data = s:_popups[a:id]
+  if s:_has_nvim
+    call nvim_win_close(data['winid'], 1)
+    let data['winid'] = 0
+  else
+    call popup_close(data['winid'])
+  endif
+  call s:_notify(a:id, {}, 'close')
+  call remove(s:_popups, a:id)
+endfunction
+
+function! s:hide(id) abort
+  let data = s:_popups[a:id]
+  if s:_has_nvim
+    call nvim_win_close(data['winid'], 1)
+    let data['winid'] = 0
+  else
+    call popup_hide(data['winid'])
+  endif
+  call s:_notify(a:id, {}, 'hide')
+endfunction
+
+function! s:show(id) abort
+  let data = s:_popups[a:id]
+  if s:_has_nvim
+    let data['winid'] = s:_nvim_open_win(data)
+  else
+    call popup_show(data['winid'])
+  endif
+  call s:_notify(a:id, {}, 'show')
+endfunction
+
+function! s:contents(id, contents) abort
+  let data = s:_popups[a:id]
+  let data['contents'] = a:contents
+  if s:_has_nvim
+    call nvim_buf_set_lines(data['bufnr'], 0, -1, 1, a:contents)
+  else
+    call popup_settext(data['winid'], a:contents)
+  endif
+endfunction
+
+function! s:options(id, opt) abort
+  let data = s:_popups[a:id]
+  call s:_set(data, a:opt)
+  if s:_has_nvim
+    call nvim_win_set_config(data['winid'], s:_get_nvim_options(data))
+  else
+    call popup_setoptions(data['winid'], s:_get_vim_options(data))
+  endif
+  call s:_notify(a:id, {}, 'options')
+endfunction
+
+function! s:winid(id) abort
+  " can return 0 when hidden for neovim
+  return s:_popups[a:id]['winid']
+endfunction
+
+function! s:bufnr(id) abort
+  return s:_popups[a:id]['bufnr']
+endfunction
+
+function! s:_get_vim_options(data) abort
+  return {
+    \ 'width': a:data['w'],
+    \ 'height': a:data['h'],
+    \ 'minwidth': a:data['w'],
+    \ 'minheight': a:data['h'],
+    \ 'maxwidth': a:data['w'],
+    \ 'maxheight': a:data['h'],
+    \ 'col': a:data['sx'],
+    \ 'line': a:data['sy'],
+    \ 'scrollbar': 0,
+    \ 'wrap': 0,
+    \ }
+endfunction
+
+function! s:_get_nvim_options(data) abort
+  return {
+    \ 'relative': 'editor',
+    \ 'style': 'minimal',
+    \ 'width': a:data['w'],
+    \ 'height': a:data['h'],
+    \ 'col': a:data['sx'],
+    \ 'row': a:data['sy'],
+    \ 'focusable': 0,
+    \ }
+endfunction
+
+function! s:_nvim_open_win(data) abort
+  return nvim_open_win(a:data['bufnr'], 0, s:_get_nvim_options(a:data))
+endfunction
+
+function! s:_user_to_editor_xy(val) abort
+  if s:_has_nvim
+    return a:val - 1
+  else
+    return a:val
+  endif
+endfunction
+
+function! s:_editor_to_user_xy(val) abort
+  if s:_has_nvim
+    return a:val + 1
+  else
+    return a:val
+  endif
+endfunction
+
+function! s:_set(data, opt) abort
+  " copy all callbacks to data
+  for [key, Cb] in items(a:opt)
+    if stridx(key, 'on_') == 0
+      let a:data[key] = Cb
+    endif
+  endfor
+
+  " try to set values from a:opt, if not set from a:data, if not default
+  let a:data['w'] = get(a:opt, 'w', get(a:data, 'w', 5))
+  let a:data['h'] = get(a:opt, 'h', get(a:data, 'h', 5))
+
+  if s:_has_nvim
+    " a:opt[x/y] need to normalize
+    " a:data['x/y'] already normalized
+    let a:data['x'] = has_key(a:opt, 'x') ? s:_user_to_editor_xy(a:opt['x']) : get(a:data, 'x', 0)
+    let a:data['y'] = has_key(a:opt, 'y') ? s:_user_to_editor_xy(a:opt['y']) : get(a:data, 'y', 0)
+  else
+    let a:data['x'] = get(a:opt, 'x', get(a:data, 'x', 1))
+    let a:data['y'] = get(a:opt, 'y', get(a:data, 'y', 1))
+  endif
+
+  let a:data['contents'] = get(a:opt, 'contents', get(a:data, 'contents', []))
+  let a:data['pos'] = get(a:opt, 'pos', get(a:data, 'pos', 'topleft'))
+
+  if a:data['pos'] ==# 'topleft'
+    let a:data['sx'] = a:data['x']
+    let a:data['sy'] = a:data['y']
+  elseif a:data['pos'] ==# 'topright'
+    let a:data['sx'] = a:data['x'] + a:data['w'] + 1
+    let a:data['sy'] = a:data['y']
+  elseif a:data['pos'] ==# 'bottomleft'
+    let a:data['sx'] = a:data['x']
+    let a:data['sy'] = a:data['y'] - a:data['h'] + 1
+  elseif a:data['pos'] ==# 'bottomright'
+    let a:data['sx'] = a:data['x'] + a:data['w'] + 1
+    let a:data['sy'] = a:data['y'] - a:data['h'] + 1
+  elseif a:data['pos'] ==# 'topcenter'
+    let a:data['sx'] = a:data['x'] + float2nr(a:data['x'] / 2) + 1
+    let a:data['sy'] = a:data['y'] - a:data['h']
+  elseif a:data['pos'] ==# 'bottomcenter'
+    let a:data['sx'] = a:data['x'] + float2nr(a:data['x'] / 2) + 1
+    let a:data['sy'] = a:data['y'] + 1
+  else
+    throw 'vital: Experimental.UI.Popup: Invalid pos'
+  endif
+endfunction
+
+function! s:_nextid() abort
+  let s:_id += 1
+  return s:_id
+endfunction
+
+function! s:_notify(id, data, event) abort
+  if has_key(s:_popups[a:id], 'on_event')
+    call s:_popups[a:id]['on_event'](a:id, a:data, a:event)
+  endif
+  let eventhandler = 'on_' . a:event
+  if has_key(s:_popups[a:id], eventhandler)
+    call s:_popups[a:id][eventhandler](a:id, a:data, a:event)
+  endif
+endfunction
+
+let &cpo = s:save_cpo
+unlet s:save_cpo
+"vim: sts=2 sw=2 smarttab et ai textwidth=0 fdm=marker
diff --git a/autoload/vital/popup.vim b/autoload/vital/popup.vim
new file mode 100644
index 000000000..6730f4e0a
--- /dev/null
+++ b/autoload/vital/popup.vim
@@ -0,0 +1,330 @@
+let s:plugin_name = expand('<sfile>:t:r')
+let s:vital_base_dir = expand('<sfile>:h')
+let s:project_root = expand('<sfile>:h:h:h')
+let s:is_vital_vim = s:plugin_name is# 'vital'
+
+let s:loaded = {}
+let s:cache_sid = {}
+
+function! vital#{s:plugin_name}#new() abort
+  return s:new(s:plugin_name)
+endfunction
+
+function! vital#{s:plugin_name}#import(...) abort
+  if !exists('s:V')
+    let s:V = s:new(s:plugin_name)
+  endif
+  return call(s:V.import, a:000, s:V)
+endfunction
+
+let s:Vital = {}
+
+function! s:new(plugin_name) abort
+  let base = deepcopy(s:Vital)
+  let base._plugin_name = a:plugin_name
+  return base
+endfunction
+
+function! s:vital_files() abort
+  if !exists('s:vital_files')
+    let s:vital_files = map(
+    \   s:is_vital_vim ? s:_global_vital_files() : s:_self_vital_files(),
+    \   'fnamemodify(v:val, ":p:gs?[\\\\/]?/?")')
+  endif
+  return copy(s:vital_files)
+endfunction
+let s:Vital.vital_files = function('s:vital_files')
+
+function! s:import(name, ...) abort dict
+  let target = {}
+  let functions = []
+  for a in a:000
+    if type(a) == type({})
+      let target = a
+    elseif type(a) == type([])
+      let functions = a
+    endif
+    unlet a
+  endfor
+  let module = self._import(a:name)
+  if empty(functions)
+    call extend(target, module, 'keep')
+  else
+    for f in functions
+      if has_key(module, f) && !has_key(target, f)
+        let target[f] = module[f]
+      endif
+    endfor
+  endif
+  return target
+endfunction
+let s:Vital.import = function('s:import')
+
+function! s:load(...) abort dict
+  for arg in a:000
+    let [name; as] = type(arg) == type([]) ? arg[: 1] : [arg, arg]
+    let target = split(join(as, ''), '\W\+')
+    let dict = self
+    let dict_type = type({})
+    while !empty(target)
+      let ns = remove(target, 0)
+      if !has_key(dict, ns)
+        let dict[ns] = {}
+      endif
+      if type(dict[ns]) == dict_type
+        let dict = dict[ns]
+      else
+        unlet dict
+        break
+      endif
+    endwhile
+    if exists('dict')
+      call extend(dict, self._import(name))
+    endif
+    unlet arg
+  endfor
+  return self
+endfunction
+let s:Vital.load = function('s:load')
+
+function! s:unload() abort dict
+  let s:loaded = {}
+  let s:cache_sid = {}
+  unlet! s:vital_files
+endfunction
+let s:Vital.unload = function('s:unload')
+
+function! s:exists(name) abort dict
+  if a:name !~# '\v^\u\w*%(\.\u\w*)*$'
+    throw 'vital: Invalid module name: ' . a:name
+  endif
+  return s:_module_path(a:name) isnot# ''
+endfunction
+let s:Vital.exists = function('s:exists')
+
+function! s:search(pattern) abort dict
+  let paths = s:_extract_files(a:pattern, self.vital_files())
+  let modules = sort(map(paths, 's:_file2module(v:val)'))
+  return uniq(modules)
+endfunction
+let s:Vital.search = function('s:search')
+
+function! s:plugin_name() abort dict
+  return self._plugin_name
+endfunction
+let s:Vital.plugin_name = function('s:plugin_name')
+
+function! s:_self_vital_files() abort
+  let builtin = printf('%s/__%s__/', s:vital_base_dir, s:plugin_name)
+  let installed = printf('%s/_%s/', s:vital_base_dir, s:plugin_name)
+  let base = builtin . ',' . installed
+  return split(globpath(base, '**/*.vim', 1), "\n")
+endfunction
+
+function! s:_global_vital_files() abort
+  let pattern = 'autoload/vital/__*__/**/*.vim'
+  return split(globpath(&runtimepath, pattern, 1), "\n")
+endfunction
+
+function! s:_extract_files(pattern, files) abort
+  let tr = {'.': '/', '*': '[^/]*', '**': '.*'}
+  let target = substitute(a:pattern, '\.\|\*\*\?', '\=tr[submatch(0)]', 'g')
+  let regexp = printf('autoload/vital/[^/]\+/%s.vim$', target)
+  return filter(a:files, 'v:val =~# regexp')
+endfunction
+
+function! s:_file2module(file) abort
+  let filename = fnamemodify(a:file, ':p:gs?[\\/]?/?')
+  let tail = matchstr(filename, 'autoload/vital/_\w\+/\zs.*\ze\.vim$')
+  return join(split(tail, '[\\/]\+'), '.')
+endfunction
+
+" @param {string} name e.g. Data.List
+function! s:_import(name) abort dict
+  if has_key(s:loaded, a:name)
+    return copy(s:loaded[a:name])
+  endif
+  let module = self._get_module(a:name)
+  if has_key(module, '_vital_created')
+    call module._vital_created(module)
+  endif
+  let export_module = filter(copy(module), 'v:key =~# "^\\a"')
+  " Cache module before calling module._vital_loaded() to avoid cyclic
+  " dependences but remove the cache if module._vital_loaded() fails.
+  " let s:loaded[a:name] = export_module
+  let s:loaded[a:name] = export_module
+  if has_key(module, '_vital_loaded')
+    try
+      call module._vital_loaded(vital#{s:plugin_name}#new())
+    catch
+      unlet s:loaded[a:name]
+      throw 'vital: fail to call ._vital_loaded(): ' . v:exception . " from:\n" . s:_format_throwpoint(v:throwpoint)
+    endtry
+  endif
+  return copy(s:loaded[a:name])
+endfunction
+let s:Vital._import = function('s:_import')
+
+function! s:_format_throwpoint(throwpoint) abort
+  let funcs = []
+  let stack = matchstr(a:throwpoint, '^function \zs.*, .\{-} \d\+$')
+  for line in split(stack, '\.\.')
+    let m = matchlist(line, '^\(.\+\)\%(\[\(\d\+\)\]\|, .\{-} \(\d\+\)\)$')
+    if !empty(m)
+      let [name, lnum, lnum2] = m[1:3]
+      if empty(lnum)
+        let lnum = lnum2
+      endif
+      let info = s:_get_func_info(name)
+      if !empty(info)
+        let attrs = empty(info.attrs) ? '' : join([''] + info.attrs)
+        let flnum = info.lnum == 0 ? '' : printf(' Line:%d', info.lnum + lnum)
+        call add(funcs, printf('function %s(...)%s Line:%d (%s%s)',
+        \        info.funcname, attrs, lnum, info.filename, flnum))
+        continue
+      endif
+    endif
+    " fallback when function information cannot be detected
+    call add(funcs, line)
+  endfor
+  return join(funcs, "\n")
+endfunction
+
+function! s:_get_func_info(name) abort
+  let name = a:name
+  if a:name =~# '^\d\+$'  " is anonymous-function
+    let name = printf('{%s}', a:name)
+  elseif a:name =~# '^<lambda>\d\+$'  " is lambda-function
+    let name = printf("{'%s'}", a:name)
+  endif
+  if !exists('*' . name)
+    return {}
+  endif
+  let body = execute(printf('verbose function %s', name))
+  let lines = split(body, "\n")
+  let signature = matchstr(lines[0], '^\s*\zs.*')
+  let [_, file, lnum; __] = matchlist(lines[1],
+  \   '^\t\%(Last set from\|.\{-}:\)\s*\zs\(.\{-}\)\%( \S\+ \(\d\+\)\)\?$')
+  return {
+  \   'filename': substitute(file, '[/\\]\+', '/', 'g'),
+  \   'lnum': 0 + lnum,
+  \   'funcname': a:name,
+  \   'arguments': split(matchstr(signature, '(\zs.*\ze)'), '\s*,\s*'),
+  \   'attrs': filter(['dict', 'abort', 'range', 'closure'], 'signature =~# (").*" . v:val)'),
+  \ }
+endfunction
+
+" s:_get_module() returns module object wihch has all script local functions.
+function! s:_get_module(name) abort dict
+  let funcname = s:_import_func_name(self.plugin_name(), a:name)
+  try
+    return call(funcname, [])
+  catch /^Vim\%((\a\+)\)\?:E117:/
+    return s:_get_builtin_module(a:name)
+  endtry
+endfunction
+
+function! s:_get_builtin_module(name) abort
+ return s:sid2sfuncs(s:_module_sid(a:name))
+endfunction
+
+if s:is_vital_vim
+  " For vital.vim, we can use s:_get_builtin_module directly
+  let s:Vital._get_module = function('s:_get_builtin_module')
+else
+  let s:Vital._get_module = function('s:_get_module')
+endif
+
+function! s:_import_func_name(plugin_name, module_name) abort
+  return printf('vital#_%s#%s#import', a:plugin_name, s:_dot_to_sharp(a:module_name))
+endfunction
+
+function! s:_module_sid(name) abort
+  let path = s:_module_path(a:name)
+  if !filereadable(path)
+    throw 'vital: module not found: ' . a:name
+  endif
+  let vital_dir = s:is_vital_vim ? '__\w\+__' : printf('_\{1,2}%s\%%(__\)\?', s:plugin_name)
+  let base = join([vital_dir, ''], '[/\\]\+')
+  let p = base . substitute('' . a:name, '\.', '[/\\\\]\\+', 'g')
+  let sid = s:_sid(path, p)
+  if !sid
+    call s:_source(path)
+    let sid = s:_sid(path, p)
+    if !sid
+      throw printf('vital: cannot get <SID> from path: %s', path)
+    endif
+  endif
+  return sid
+endfunction
+
+function! s:_module_path(name) abort
+  return get(s:_extract_files(a:name, s:vital_files()), 0, '')
+endfunction
+
+function! s:_module_sid_base_dir() abort
+  return s:is_vital_vim ? &rtp : s:project_root
+endfunction
+
+function! s:_dot_to_sharp(name) abort
+  return substitute(a:name, '\.', '#', 'g')
+endfunction
+
+function! s:_source(path) abort
+  execute 'source' fnameescape(a:path)
+endfunction
+
+" @vimlint(EVL102, 1, l:_)
+" @vimlint(EVL102, 1, l:__)
+function! s:_sid(path, filter_pattern) abort
+  let unified_path = s:_unify_path(a:path)
+  if has_key(s:cache_sid, unified_path)
+    return s:cache_sid[unified_path]
+  endif
+  for line in filter(split(execute(':scriptnames'), "\n"), 'v:val =~# a:filter_pattern')
+    let [_, sid, path; __] = matchlist(line, '^\s*\(\d\+\):\s\+\(.\+\)\s*$')
+    if s:_unify_path(path) is# unified_path
+      let s:cache_sid[unified_path] = sid
+      return s:cache_sid[unified_path]
+    endif
+  endfor
+  return 0
+endfunction
+
+if filereadable(expand('<sfile>:r') . '.VIM') " is case-insensitive or not
+  let s:_unify_path_cache = {}
+  " resolve() is slow, so we cache results.
+  " Note: On windows, vim can't expand path names from 8.3 formats.
+  " So if getting full path via <sfile> and $HOME was set as 8.3 format,
+  " vital load duplicated scripts. Below's :~ avoid this issue.
+  function! s:_unify_path(path) abort
+    if has_key(s:_unify_path_cache, a:path)
+      return s:_unify_path_cache[a:path]
+    endif
+    let value = tolower(fnamemodify(resolve(fnamemodify(
+    \                   a:path, ':p')), ':~:gs?[\\/]?/?'))
+    let s:_unify_path_cache[a:path] = value
+    return value
+  endfunction
+else
+  function! s:_unify_path(path) abort
+    return resolve(fnamemodify(a:path, ':p:gs?[\\/]?/?'))
+  endfunction
+endif
+
+" copied and modified from Vim.ScriptLocal
+let s:SNR = join(map(range(len("\<SNR>")), '"[\\x" . printf("%0x", char2nr("\<SNR>"[v:val])) . "]"'), '')
+function! s:sid2sfuncs(sid) abort
+  let fs = split(execute(printf(':function /^%s%s_', s:SNR, a:sid)), "\n")
+  let r = {}
+  let pattern = printf('\m^function\s<SNR>%d_\zs\w\{-}\ze(', a:sid)
+  for fname in map(fs, 'matchstr(v:val, pattern)')
+    let r[fname] = function(s:_sfuncname(a:sid, fname))
+  endfor
+  return r
+endfunction
+
+"" Return funcname of script local functions with SID
+function! s:_sfuncname(sid, funcname) abort
+  return printf('<SNR>%s_%s', a:sid, a:funcname)
+endfunction
diff --git a/autoload/vital/popup.vital b/autoload/vital/popup.vital
new file mode 100644
index 000000000..f33a96cbe
--- /dev/null
+++ b/autoload/vital/popup.vital
@@ -0,0 +1,4 @@
+popup
+6c4c07f2d140c7d61ad00bd756e299535d6b04cc
+
+Experimental.UI.Popup