new file mode 100644
--- /dev/null
+++ b/runtime/syntax/autodoc.vim
@@ -0,0 +1,101 @@
+" Vim syntax file
+" Language:	Autodoc
+" Maintainer:	Stephen R. van den Berg <srb@cuci.nl>
+" Last Change:	2018 Jan 23
+" Version:	2.9
+" Remark:       Included by pike.vim, cmod.vim and optionally c.vim
+" Remark:       In order to make c.vim use it, set: c_autodoc
+
+" Quit when a (custom) syntax file was already loaded
+if exists("b:current_syntax")
+  finish
+endif
+
+let s:cpo_save = &cpo
+set cpo&vim
+
+syn case match
+
+" A bunch of useful autodoc keywords
+syn keyword autodocStatement contained appears belongs global
+syn keyword autodocStatement contained decl directive inherit
+syn keyword autodocStatement contained deprecated obsolete bugs
+syn keyword autodocStatement contained copyright example fixme note param returns
+syn keyword autodocStatement contained seealso thanks throws constant
+syn keyword autodocStatement contained member index elem
+syn keyword autodocStatement contained value type item
+
+syn keyword autodocRegion contained enum mapping code multiset array
+syn keyword autodocRegion contained int string section mixed ol ul dl
+syn keyword autodocRegion contained class module namespace
+syn keyword autodocRegion contained endenum endmapping endcode endmultiset
+syn keyword autodocRegion contained endarray endint endstring endsection
+syn keyword autodocRegion contained endmixed endol endul enddl
+syn keyword autodocRegion contained endclass endmodule endnamespace
+
+syn keyword autodocIgnore contained ignore endignore
+
+syn keyword autodocStatAcc contained b i u tt url pre sub sup
+syn keyword autodocStatAcc contained ref rfc xml dl expr image
+
+syn keyword	autodocTodo		contained TODO FIXME XXX
+
+syn match autodocLineStart	display "\(//\|/\?\*\)\@2<=!"
+syn match autodocWords "[^!@{}[\]]\+" display contains=@Spell
+
+syn match autodocLink "@\[[^[\]]\+]"hs=s+2,he=e-1 display contains=autodocLead
+syn match autodocAtStmt "@[a-z]\+\%(\s\|$\)\@="hs=s+1 display contains=autodocStatement,autodocIgnore,autodocLead,autodocRegion
+
+" Due to limitations of the matching algorithm, we cannot highlight
+" nested autodocNStmtAcc structures correctly
+syn region autodocNStmtAcc start="@[a-z]\+{" end="@}" contains=autodocStatAcc,autodocLead keepend
+
+syn match autodocUrl contained display ".\+"
+syn region autodocAtUrlAcc start="{"ms=s+1 end="@}"he=e-1,me=e-2 contained display contains=autodocUrl,autodocLead keepend
+syn region autodocNUrlAcc start="@url{" end="@}" contains=autodocStatAcc,autodocAtUrlAcc,autodocLead transparent
+
+syn match autodocSpecial "@@" display
+syn match autodocLead "@" display contained
+
+"when wanted, highlight trailing white space
+if exists("c_space_errors")
+  if !exists("c_no_trail_space_error")
+    syn match	autodocSpaceError	display excludenl "\s\+$"
+  endif
+  if !exists("c_no_tab_space_error")
+    syn match	autodocSpaceError	display " \+\t"me=e-1
+  endif
+endif
+
+if exists("c_minlines")
+  let b:c_minlines = c_minlines
+else
+  if !exists("c_no_if0")
+    let b:c_minlines = 50	" #if 0 constructs can be long
+  else
+    let b:c_minlines = 15	" mostly for () constructs
+  endif
+endif
+exec "syn sync ccomment autodocComment minlines=" . b:c_minlines
+
+" Define the default highlighting.
+" Only used when an item doesn't have highlighting yet
+hi def link autodocStatement	Statement
+hi def link autodocStatAcc	Statement
+hi def link autodocRegion	Structure
+hi def link autodocAtStmt	Error
+hi def link autodocNStmtAcc	Identifier
+hi def link autodocLink		Type
+hi def link autodocTodo		Todo
+hi def link autodocSpaceError	Error
+hi def link autodocLineStart	SpecialComment
+hi def link autodocSpecial	SpecialChar
+hi def link autodocUrl		Underlined
+hi def link autodocLead		Statement
+hi def link autodocIgnore	Delimiter
+
+let b:current_syntax = "autodoc"
+
+let &cpo = s:cpo_save
+unlet s:cpo_save
+" vim: ts=8