diff --git a/autoload/openbrowser.vim b/autoload/openbrowser.vim
index 0fd99de..2487b1a 100644
--- a/autoload/openbrowser.vim
+++ b/autoload/openbrowser.vim
@@ -6,15 +6,17 @@ let s:save_cpo = &cpo
 set cpo&vim
 " }}}
 
-let s:V = vital#openbrowser#new()
-let s:Prelude = s:V.import('Prelude')
-let s:String = s:V.import('Data.String')
-let s:Process = s:V.import('Process')
-let s:URI = s:V.import('Web.URI')
-let s:HTTP = s:V.import('Web.HTTP')
-let s:Buffer = s:V.import('Vim.Buffer')
-let s:Msg = s:V.import('Vim.Message')
-unlet s:V
+let s:Prelude = vital#openbrowser#import('Prelude')
+let s:String = vital#openbrowser#import('Data.String')
+let s:Process = vital#openbrowser#import('System.Process')
+let s:URI = vital#openbrowser#import('Web.URI')
+let s:HTTP = vital#openbrowser#import('Web.HTTP')
+let s:Buffer = vital#openbrowser#import('Vim.Buffer')
+let s:Msg = vital#openbrowser#import('Vim.Message')
+
+let s:t_string = type('')
+let s:t_dict = type({})
+let s:t_list = type([])
 
 
 " Save/Determine global variable values.
@@ -23,7 +25,7 @@ let s:vimproc_is_installed = globpath(&rtp, 'autoload/vimproc.vim') !=# ''
 
 " Interfaces {{{
 
-function! openbrowser#load() "{{{
+function! openbrowser#load() abort "{{{
   " dummy function to load this file.
 endfunction "}}}
 
@@ -31,14 +33,14 @@ endfunction "}}}
 
 " :OpenBrowser
 " @param uri URI object or String
-function! openbrowser#open(uri) "{{{
-  if type(a:uri) is type({})
+function! openbrowser#open(uri) abort "{{{
+  if type(a:uri) is s:t_list
   \   && has_key(a:uri, '__pattern_set')    " URI object
     " Trust URI object value because
     " it must be validated by parser.
     let uriobj = a:uri
     let uristr = a:uri.to_string()
-  elseif type(a:uri) is type("")
+  elseif type(a:uri) is s:t_string
     let uristr = a:uri
     if uristr =~# '^\s*$'
       return
@@ -108,7 +110,7 @@ function! openbrowser#open(uri) "{{{
 endfunction "}}}
 
 " :OpenBrowserSearch
-function! openbrowser#search(query, ...) "{{{
+function! openbrowser#search(query, ...) abort "{{{
   if a:query =~# '^\s*$'
     return
   endif
@@ -128,7 +130,7 @@ function! openbrowser#search(query, ...) "{{{
 endfunction "}}}
 
 " :OpenBrowserSmartSearch
-function! openbrowser#smart_search(query, ...) "{{{
+function! openbrowser#smart_search(query, ...) abort "{{{
   let type = s:detect_query_type(a:query)
   if type.uri || type.filepath
     return openbrowser#open(a:query)
@@ -140,11 +142,6 @@ function! openbrowser#smart_search(query, ...) "{{{
   endif
 endfunction "}}}
 
-" Escape one argument.
-function! openbrowser#shellescape(...) "{{{
-  return call(s:Process.shellescape, a:000, s:Process)
-endfunction "}}}
-
 " }}}
 
 " Implementations {{{
@@ -154,7 +151,7 @@ lockvar s:NONE
 
 
 
-function! s:parse_and_delegate(excmd, parse, delegate, cmdline) "{{{
+function! s:parse_and_delegate(excmd, parse, delegate, cmdline) abort "{{{
   let cmdline = substitute(a:cmdline, '^\s\+', '', '')
 
   try
@@ -171,13 +168,13 @@ function! s:parse_and_delegate(excmd, parse, delegate, cmdline) "{{{
   let args = [cmdline] + (engine is s:NONE ? [] : [engine])
   return call(a:delegate, args)
 endfunction "}}}
-function! s:parse_cmdline(cmdline) "{{{
+function! s:parse_cmdline(cmdline) abort "{{{
   let m = matchlist(a:cmdline, '^-\(\S\+\)\s\+\(.*\)')
   return !empty(m) ? m[1:2] : [s:NONE, a:cmdline]
 endfunction "}}}
 
 " :OpenBrowserSearch
-function! openbrowser#_cmd_open_browser_search(cmdline) "{{{
+function! openbrowser#_cmd_open_browser_search(cmdline) abort "{{{
   return s:parse_and_delegate(
   \   ':OpenBrowserSearch',
   \   's:parse_cmdline',
@@ -187,7 +184,7 @@ function! openbrowser#_cmd_open_browser_search(cmdline) "{{{
 endfunction "}}}
 " @vimlint(EVL103, 1, a:arglead)
 " @vimlint(EVL103, 1, a:cursorpos)
-function! openbrowser#_cmd_complete(arglead, cmdline, cursorpos) "{{{
+function! openbrowser#_cmd_complete(arglead, cmdline, cursorpos) abort "{{{
   let excmd = '^\s*OpenBrowser\w\+\s\+'
   if a:cmdline !~# excmd
     return
@@ -196,7 +193,7 @@ function! openbrowser#_cmd_complete(arglead, cmdline, cursorpos) "{{{
 
   let engine_options = map(
   \   sort(keys(s:get_var('openbrowser_search_engines'))),
-  \   '"-" . v:val'
+  \   '''-'' . v:val'
   \)
   if cmdline ==# '' || cmdline ==# '-'
     " Return all search engines.
@@ -211,7 +208,7 @@ endfunction "}}}
 " @vimlint(EVL103, 0, a:cursorpos)
 
 " :OpenBrowserSmartSearch
-function! openbrowser#_cmd_open_browser_smart_search(cmdline) "{{{
+function! openbrowser#_cmd_open_browser_smart_search(cmdline) abort "{{{
   return s:parse_and_delegate(
   \   ':OpenBrowserSmartSearch',
   \   's:parse_cmdline',
@@ -221,7 +218,7 @@ function! openbrowser#_cmd_open_browser_smart_search(cmdline) "{{{
 endfunction "}}}
 
 " <Plug>(openbrowser-open)
-function! openbrowser#_keymapping_open(mode, ...) "{{{
+function! openbrowser#_keymapping_open(mode, ...) abort "{{{
   let silent = get(a:000, 0, s:get_var('openbrowser_message_verbosity') ==# 0)
   if a:mode ==# 'n'
     " URL
@@ -239,7 +236,7 @@ function! openbrowser#_keymapping_open(mode, ...) "{{{
     " Fail!
     if !silent
       call s:Msg.error(
-      \   "URL or file path is not found under cursor!")
+      \   'URL or file path is not found under cursor!')
     endif
     return 0
   else
@@ -253,7 +250,7 @@ function! openbrowser#_keymapping_open(mode, ...) "{{{
 endfunction "}}}
 
 " <Plug>(openbrowser-search)
-function! openbrowser#_keymapping_search(mode) "{{{
+function! openbrowser#_keymapping_search(mode) abort "{{{
   if a:mode ==# 'n'
     return openbrowser#search(expand('<cword>'))
   else
@@ -262,7 +259,7 @@ function! openbrowser#_keymapping_search(mode) "{{{
 endfunction "}}}
 
 " <Plug>(openbrowser-smart-search)
-function! openbrowser#_keymapping_smart_search(mode) "{{{
+function! openbrowser#_keymapping_smart_search(mode) abort "{{{
   if openbrowser#_keymapping_open(a:mode, 1)
     " Suceeded to open!
     return
@@ -281,7 +278,7 @@ function! openbrowser#_keymapping_smart_search(mode) "{{{
   endif
 endfunction "}}}
 
-function! s:get_selected_text() "{{{
+function! s:get_selected_text() abort "{{{
   let selected_text = s:Buffer.get_last_selected()
   let text = substitute(selected_text, '[\n\r]\+', ' ', 'g')
   return substitute(text, '^\s*\|\s*$', '', 'g')
@@ -363,7 +360,7 @@ function! s:extract_urls(text) abort "{{{
   return urls
 endfunction "}}}
 
-function! s:seems_path(uri) "{{{
+function! s:seems_path(uri) abort "{{{
   " - Has no invalid filename character (seeing &isfname)
   " and, either
   " - file:// prefixed string and existed file path
@@ -376,12 +373,12 @@ function! s:seems_path(uri) "{{{
   return getftype(path) !=# ''
 endfunction "}}}
 
-function! s:seems_uri(uriobj) "{{{
+function! s:seems_uri(uriobj) abort "{{{
   return !empty(a:uriobj)
   \   && a:uriobj.scheme() !=# ''
 endfunction "}}}
 
-function! s:detect_query_type(query, ...) "{{{
+function! s:detect_query_type(query, ...) abort "{{{
   let uriobj = a:0 ? a:1 : {}
   if empty(uriobj)
     let uriobj = s:URI.new(a:query, {})
@@ -393,7 +390,7 @@ function! s:detect_query_type(query, ...) "{{{
 endfunction "}}}
 
 " @vimlint(EVL104, 1, l:save_shellslash)
-function! s:convert_to_fullpath(path) "{{{
+function! s:convert_to_fullpath(path) abort "{{{
   if exists('+shellslash')
     let save_shellslash = &l:shellslash
     let &l:shellslash = 1
@@ -408,7 +405,7 @@ function! s:convert_to_fullpath(path) "{{{
 endfunction "}}}
 " @vimlint(EVL104, 0, l:save_shellslash)
 
-function! s:expand_format_message(format_message, keywords) "{{{
+function! s:expand_format_message(format_message, keywords) abort "{{{
   let maxlen = s:Msg.get_hit_enter_max_length()
   let expanded_msg = s:expand_keywords(a:format_message.msg, a:keywords)
   if a:format_message.truncate && strlen(expanded_msg) > maxlen
@@ -447,7 +444,7 @@ endfunction "}}}
 
 " @param uristr String
 " This function is public for testing.
-function! openbrowser#__open_browser__(uristr) "{{{
+function! openbrowser#__open_browser__(uristr) abort "{{{
   let uri = a:uristr
 
   " Clear previous message
@@ -473,25 +470,25 @@ function! openbrowser#__open_browser__(uristr) "{{{
     " If args is not List, need to escape by open-browser,
     " not s:Process.system().
     let args = deepcopy(cmd.args)
-    let need_escape = type(args) isnot type([])
+    let need_escape = type(args) isnot s:t_list
     let quote = need_escape ? "'" : ''
     let use_vimproc = (g:openbrowser_use_vimproc && s:vimproc_is_installed)
     let system_args = map(
-    \   (type(args) is type([]) ? copy(args) : [args]),
+    \   (type(args) is s:t_list ? copy(args) : [args]),
     \   's:expand_keywords(
     \      v:val,
     \      {
-    \           "browser"      : quote . cmd.name . quote,
-    \           "browser_noesc": cmd.name,
-    \           "uri"          : quote . uri . quote,
-    \           "uri_noesc"    : uri,
-    \           "use_vimproc"  : use_vimproc,
+    \           ''browser''      : quote . cmd.name . quote,
+    \           ''browser_noesc'': cmd.name,
+    \           ''uri''          : quote . uri . quote,
+    \           ''uri_noesc''    : uri,
+    \           ''use_vimproc''  : use_vimproc,
     \       }
     \   )'
     \)
     try
       call openbrowser#__system__(
-      \   (type(args) is type([]) ? system_args : system_args[0]),
+      \   (type(args) is s:t_list ? system_args : system_args[0]),
       \   {'use_vimproc': use_vimproc,
       \    'background': get(cmd, 'background')}
       \)
@@ -523,21 +520,21 @@ function! openbrowser#__open_browser__(uristr) "{{{
   return 0
 endfunction "}}}
 
-function! openbrowser#__system__(...)
-  return call(s:Process.system, a:000, s:Process)
+function! openbrowser#__system__(...) abort
+  return call(s:Process.execute, a:000, s:Process)
 endfunction
 
 " @return Dictionary: the URL on cursor, or the first URL after cursor
 "   Empty Dictionary means no URLs found.
 " :help openbrowser-url-detection
-function! s:get_url_on_cursor() "{{{
+function! s:get_url_on_cursor() abort "{{{
   let url = s:get_thing_on_cursor('s:detect_url_cb')
   return url isnot s:NONE ? url : ''
 endfunction "}}}
 
 " @return the filepath on cursor, or the first filepath after cursor
 " :help openbrowser-filepath-detection
-function! s:get_filepath_on_cursor() "{{{
+function! s:get_filepath_on_cursor() abort "{{{
   let filepath = s:get_thing_on_cursor('s:detect_filepath_cb')
   return filepath isnot s:NONE ? filepath : ''
 endfunction "}}}
@@ -600,8 +597,8 @@ endfunction
 " Escape by \ if you does not want to expand.
 " - "\{keyword}" => "{keyword}", not expression `keyword`.
 "   it does not expand vim variable `keyword`.
-function! s:expand_keywords(str, options)  " {{{
-  if type(a:str) != type('') || type(a:options) != type({})
+function! s:expand_keywords(str, options) abort " {{{
+  if type(a:str) isnot s:t_string || type(a:options) isnot s:t_dict
     echoerr 's:expand_keywords(): invalid arguments. (a:str = '.string(a:str).', a:options = '.string(a:options).')'
     return ''
   endif
@@ -631,10 +628,10 @@ function! s:expand_keywords(str, options)  " {{{
     endif
 
     " Process special string.
-    if rest[0] == '\'
+    if rest[0] ==# '\'
       let result .= rest[1]
       let rest = rest[2 :]
-    elseif rest[0] == '{'
+    elseif rest[0] ==# '{'
       " NOTE: braindex + 1 == 1, it skips first bracket (rest[0])
       let braindex = 0
       let braindex_stack = [braindex]
@@ -654,7 +651,7 @@ function! s:expand_keywords(str, options)  " {{{
           let right = rest[braindex+1 :]
           " Remove(unescape) backslashes.
           let expr = substitute(expr, '\\\([{}]\)', '\1', 'g')
-          let value = eval(expr) . ""
+          let value = eval(expr) . ''
           let rest = left . value . right
           let braindex -= len(expr) - len(value)
         endif
@@ -668,7 +665,7 @@ function! s:expand_keywords(str, options)  " {{{
   return result
 endfunction "}}}
 
-function! s:get_var(varname) "{{{
+function! s:get_var(varname) abort "{{{
   for ns in [b:, w:, t:, g:]
     if has_key(ns, a:varname)
       return ns[a:varname]
@@ -679,7 +676,7 @@ function! s:get_var(varname) "{{{
 endfunction "}}}
 
 " From https://github.com/chikatoike/concealedyank.vim
-function! s:getconcealedline(lnum, ...) "{{{
+function! s:getconcealedline(lnum, ...) abort "{{{
   if !has('conceal')
     return getline(a:lnum)
   endif
@@ -710,7 +707,7 @@ function! s:getconcealedline(lnum, ...) "{{{
   return ret
 endfunction "}}}
 
-function! s:getconcealedcol(expr) "{{{
+function! s:getconcealedcol(expr) abort "{{{
   if !has('conceal')
     return col(a:expr)
   endif
@@ -741,7 +738,7 @@ function! s:getconcealedcol(expr) "{{{
   return ret
 endfunction "}}}
 
-function! s:shellslash()
+function! s:shellslash() abort
   return exists('+shellslash') && &l:shellslash
 endfunction "}}}
 
diff --git a/autoload/vital/_openbrowser/System/Process.vim b/autoload/vital/_openbrowser/System/Process.vim
new file mode 100644
index 0000000..016c052
--- /dev/null
+++ b/autoload/vital/_openbrowser/System/Process.vim
@@ -0,0 +1,102 @@
+" ___vital___
+" NOTE: lines between '" ___vital___' is generated by :Vitalize.
+" Do not mofidify the code nor insert new lines before '" ___vital___'
+if v:version > 703 || v:version == 703 && has('patch1170')
+  function! vital#_openbrowser#System#Process#import() abort
+    return map({'_vital_depends': '', 'execute': '', 'register': '', '_vital_loaded': ''},  'function("s:" . v:key)')
+  endfunction
+else
+  function! s:_SID() abort
+    return matchstr(expand('<sfile>'), '<SNR>\zs\d\+\ze__SID$')
+  endfunction
+  execute join(['function! vital#_openbrowser#System#Process#import() abort', printf("return map({'_vital_depends': '', 'execute': '', 'register': '', '_vital_loaded': ''}, \"function('<SNR>%s_' . v:key)\")", s:_SID()), 'endfunction'], "\n")
+  delfunction s:_SID
+endif
+" ___vital___
+let s:save_cpoptions = &cpoptions
+set cpoptions&vim
+
+let s:registry = {}
+let s:priority = []
+
+function! s:_vital_loaded(V) abort
+  let s:V = a:V
+  let s:Prelude = a:V.import('Prelude')
+  let s:String = a:V.import('Data.String')
+  call s:register('System.Process.Vimproc')
+  call s:register('System.Process.System')
+endfunction
+
+function! s:_vital_depends() abort
+  return [
+        \ 'Prelude',
+        \ 'Data.String',
+        \ 'System.Process.System',
+        \ 'System.Process.Vimproc',
+        \]
+endfunction
+
+function! s:_throw(msg) abort
+  throw printf('vital: System.Process: %s', a:msg)
+endfunction
+
+function! s:register(name) abort
+  let client = s:V.import(a:name)
+  if client.is_available()
+    let s:registry[a:name] = client
+    call add(s:priority, a:name)
+  endif
+endfunction
+
+function! s:_execute(args, options) abort
+  for name_or_client in a:options.clients
+    let client = s:Prelude.is_string(name_or_client)
+          \ ? s:registry[name_or_client]
+          \ : name_or_client
+    if !client.is_supported(a:options)
+      continue
+    endif
+    return client.execute(a:args, a:options)
+  endfor
+  call s:_throw(printf(
+        \ 'None of client support options : %s',
+        \ string(a:options),
+        \))
+endfunction
+
+" execute({args}[, {options}])
+function! s:execute(args, ...) abort
+  let options = extend({
+        \ 'clients': s:priority,
+        \ 'input': 0,
+        \ 'timeout': 0,
+        \ 'background': 0,
+        \ 'encode_input': 1,
+        \ 'encode_output': 1,
+        \ 'split_output': 1,
+        \ 'debug': &verbose,
+        \}, get(a:000, 0, {}))
+  if s:Prelude.is_string(options.input) && !empty(options.encode_input)
+    let encoding = s:Prelude.is_string(options.encode_input)
+          \ ? options.encode_input
+          \ : &encoding
+    let options.input = s:String.iconv(options.input, encoding, 'char')
+  endif
+  let result = s:_execute(a:args, options)
+  if s:Prelude.is_string(result.output) && !empty(options.encode_output)
+    let encoding = s:Prelude.is_string(options.encode_output)
+          \ ? options.encode_output
+          \ : &encoding
+    let result.output = s:String.iconv(result.output, 'char', encoding)
+  endif
+  if options.split_output
+    let result.content = s:String.split_posix_text(result.output)
+  endif
+  let result.success = result.status == 0
+  let result.args = a:args
+  let result.options = options
+  return result
+endfunction
+
+let &cpoptions = s:save_cpoptions
+unlet s:save_cpoptions
diff --git a/autoload/vital/_openbrowser/System/Process/System.vim b/autoload/vital/_openbrowser/System/Process/System.vim
new file mode 100644
index 0000000..f41f01e
--- /dev/null
+++ b/autoload/vital/_openbrowser/System/Process/System.vim
@@ -0,0 +1,134 @@
+" ___vital___
+" NOTE: lines between '" ___vital___' is generated by :Vitalize.
+" Do not mofidify the code nor insert new lines before '" ___vital___'
+if v:version > 703 || v:version == 703 && has('patch1170')
+  function! vital#_openbrowser#System#Process#System#import() abort
+    return map({'_vital_depends': '', 'shellescape': '', 'execute': '', 'is_supported': '', 'is_available': '', '_vital_loaded': ''},  'function("s:" . v:key)')
+  endfunction
+else
+  function! s:_SID() abort
+    return matchstr(expand('<sfile>'), '<SNR>\zs\d\+\ze__SID$')
+  endfunction
+  execute join(['function! vital#_openbrowser#System#Process#System#import() abort', printf("return map({'_vital_depends': '', 'shellescape': '', 'execute': '', 'is_supported': '', 'is_available': '', '_vital_loaded': ''}, \"function('<SNR>%s_' . v:key)\")", s:_SID()), 'endfunction'], "\n")
+  delfunction s:_SID
+endif
+" ___vital___
+let s:save_cpoptions = &cpoptions
+set cpoptions&vim
+
+function! s:_vital_loaded(V) abort
+  let s:Prelude = a:V.import('Prelude')
+  let s:String = a:V.import('Data.String')
+  let s:Guard = a:V.import('Vim.Guard')
+endfunction
+
+function! s:_vital_depends() abort
+  return [
+        \ 'Prelude',
+        \ 'Data.String',
+        \ 'Vim.Guard',
+        \]
+endfunction
+
+function! s:is_available() abort
+  return 1
+endfunction
+
+function! s:is_supported(options) abort
+  if get(a:options, 'timeout')
+    return 0
+  elseif get(a:options, 'background') && s:Prelude.is_windows()
+    return 0
+  endif
+  return 1
+endfunction
+
+function! s:shellescape(string) abort
+  if s:Prelude.is_windows()
+    " NOTE:
+    " In windows, a string which does not contain space SHOULD NOT be escaped
+    return a:string =~# '\s' ? shellescape(a:string) : a:string
+  else
+    return shellescape(a:string)
+  endif
+endfunction
+
+function! s:execute(args, options) abort
+  " NOTE:
+  " execute() is a command for executing program WITHOUT using shell.
+  " so mimic that behaviour with shell
+  let guard = s:Guard.store(filter([
+        \ '&shell',
+        \ '&shellcmdflag',
+        \ '&shellquote',
+        \ '&shellredir',
+        \ '&shelltemp',
+        \ (exists('+shelltype') ? '&shelltype' : ''),
+        \ (exists('+shellxescape') ? '&shellxescape' : ''),
+        \ (exists('+shellxquote') ? '&shellxquote' : ''),
+        \ (exists('+shellslash') ? '&shellslash' : ''),
+        \], '!empty(v:val)')
+        \)
+  try
+    " Reset shell related options
+    if s:Prelude.is_windows()
+      set shell&
+      if exists('+shellslash')
+        set shellslash&
+      endif
+    else
+      set shell=sh
+    endif
+    set shellcmdflag& shellquote& shellredir& shelltemp&
+    if exists('+shelltype')
+      set shelltype&
+    endif
+    if exists('+shellxescape')
+      set shellxescape&
+    endif
+    if exists('+shellxquote')
+      set shellxquote&
+    endif
+    let cmdline = join(map(
+          \ copy(a:args),
+          \ 's:shellescape(v:val)',
+          \))
+    if a:options.background && !s:Prelude.is_windows()
+      let cmdline = cmdline . ' &'
+    endif
+    if a:options.debug > 0
+      echomsg printf(
+            \ 'vital: System.Process.System: %s',
+            \ cmdline
+            \)
+    endif
+    if v:version < 704 || (v:version == 704 && !has('patch122'))
+      " {cmdline} of system() before Vim 7.4.122 is not converted so convert
+      " it manually from &encoding to 'char'
+      let cmdline = s:String.iconv(cmdline, &encoding, 'char')
+    endif
+    let args = [cmdline] + (s:Prelude.is_string(a:options.input) ? [a:options.input] : [])
+    let output = call('system', args)
+    if s:Prelude.is_windows()
+      " A builtin system() add a trailing space in Windows.
+      " It is probably an issue of pipe in Windows so remove it.
+      let output = substitute(output, '\s\n$', '\n', '')
+    endif
+    " NOTE:
+    " Vim 7.4 always return exit_status:0 for background process so mimic
+    let status = a:options.background ? 0 : v:shell_error
+    " NOTE:
+    " status, output are COMMON information
+    " cmdline is an EXTRA information
+    return {
+          \ 'status': status,
+          \ 'output': output,
+          \ 'cmdline': cmdline,
+          \}
+  finally
+    call guard.restore()
+  endtry
+endfunction
+
+let &cpoptions = s:save_cpoptions
+unlet s:save_cpoptions
diff --git a/autoload/vital/_openbrowser/System/Process/Vimproc.vim b/autoload/vital/_openbrowser/System/Process/Vimproc.vim
new file mode 100644
index 0000000..08f19fc
--- /dev/null
+++ b/autoload/vital/_openbrowser/System/Process/Vimproc.vim
@@ -0,0 +1,88 @@
+" ___vital___
+" NOTE: lines between '" ___vital___' is generated by :Vitalize.
+" Do not mofidify the code nor insert new lines before '" ___vital___'
+if v:version > 703 || v:version == 703 && has('patch1170')
+  function! vital#_openbrowser#System#Process#Vimproc#import() abort
+    return map({'_vital_depends': '', 'execute': '', 'is_supported': '', 'is_available': '', '_vital_loaded': ''},  'function("s:" . v:key)')
+  endfunction
+else
+  function! s:_SID() abort
+    return matchstr(expand('<sfile>'), '<SNR>\zs\d\+\ze__SID$')
+  endfunction
+  execute join(['function! vital#_openbrowser#System#Process#Vimproc#import() abort', printf("return map({'_vital_depends': '', 'execute': '', 'is_supported': '', 'is_available': '', '_vital_loaded': ''}, \"function('<SNR>%s_' . v:key)\")", s:_SID()), 'endfunction'], "\n")
+  delfunction s:_SID
+endif
+" ___vital___
+let s:save_cpoptions = &cpoptions
+set cpoptions&vim
+
+function! s:_vital_loaded(V) abort
+  let s:Prelude = a:V.import('Prelude')
+endfunction
+
+function! s:_vital_depends() abort
+  return [
+        \ 'Prelude',
+        \]
+endfunction
+
+function! s:is_available() abort
+  if exists('s:vimproc_available')
+    return s:vimproc_available
+  endif
+  try
+    call vimproc#version()
+    let s:vimproc_available = 1
+  catch
+    let s:vimproc_available = 0
+  endtry
+  return s:vimproc_available
+endfunction
+
+function! s:is_supported(options) abort
+  if get(a:options, 'background') && (
+        \   s:Prelude.is_string(get(a:options, 'input')) ||
+        \   get(a:options, 'timeout')
+        \)
+    return 0
+  endif
+  return 1
+endfunction
+
+function! s:execute(args, options) abort
+  let cmdline = join(map(
+        \ copy(a:args),
+        \ 'vimproc#shellescape(v:val)',
+        \))
+  if a:options.debug > 0
+    echomsg printf(
+          \ 'vital: System.Process.Vimproc: %s',
+          \ cmdline
+          \)
+  endif
+  if a:options.background
+    let output = vimproc#system_bg(cmdline)
+    " NOTE:
+    " background process via Builtin always return exit_code:0 so mimic
+    let status = 0
+  else
+    let output = vimproc#system(
+          \ cmdline,
+          \ s:Prelude.is_string(a:options.input) ? a:options.input : '',
+          \ a:options.timeout,
+          \)
+    let status = vimproc#get_last_status()
+  endif
+    " NOTE:
+    " status, output are COMMON information
+    " errormsg, cmdline are EXTRA information
+  return {
+        \ 'status': status,
+        \ 'output': output,
+        \ 'errormsg': vimproc#get_last_errmsg(),
+        \ 'cmdline': cmdline,
+        \}
+endfunction
+
+let &cpoptions = s:save_cpoptions
+unlet s:save_cpoptions
diff --git a/autoload/vital/openbrowser.vital b/autoload/vital/openbrowser.vital
index ba17fb7..b13e438 100644
--- a/autoload/vital/openbrowser.vital
+++ b/autoload/vital/openbrowser.vital
@@ -1,9 +1,10 @@
 openbrowser
 8b5b32ae61c863bf8d930921a9213687774327d1
 
-Process
 Web.URI
 Web.HTTP
 Vim.Buffer
 Prelude
 Vim.Message
+System.Process
+Process
diff --git a/plugin/openbrowser.vim b/plugin/openbrowser.vim
index eb2eaec..e0e22c1 100644
--- a/plugin/openbrowser.vim
+++ b/plugin/openbrowser.vim
@@ -13,6 +13,7 @@ set cpo&vim
 " }}}
 
 
+let s:t_string = type('')
 let s:is_unix = has('unix')
 let s:is_mswin = has('win16') || has('win32') || has('win64')
 let s:is_cygwin = has('win32unix')
@@ -183,7 +184,7 @@ let s:FORMAT_MESSAGE_DEFAULT = {
 \}
 if !exists('g:openbrowser_format_message')
   let g:openbrowser_format_message = s:FORMAT_MESSAGE_DEFAULT
-elseif type(g:openbrowser_format_message) is type("")
+elseif type(g:openbrowser_format_message) is s:t_string
   " Backward-compatibility
   let s:msg = g:openbrowser_format_message
   unlet g:openbrowser_format_message