diff --git a/runtime/syntax/html.vim b/runtime/syntax/html.vim
index 8ccb557..9061bde 100644
--- a/runtime/syntax/html.vim
+++ b/runtime/syntax/html.vim
@@ -1,12 +1,9 @@
 " Vim syntax file
-" Language:             HTML
-" Previous Maintainer:  Jorge Maldonado Ventura <jorgesumle@freakspot.net>
-" Previous Maintainer:  Claudio Fleiner <claudio@fleiner.com>
-" Repository:           https://notabug.org/jorgesumle/vim-html-syntax
-" Last Change:          2021 Mar 02
-"			Included patch #7900 to fix comments
-"			Included patch #7916 to fix a few more things
-"
+" Language:		HTML
+" Maintainer:		Doug Kearns <dougkearns@gmail.com>
+" Previous Maintainers: Jorge Maldonado Ventura <jorgesumle@freakspot.net>
+"			Claudio Fleiner <claudio@fleiner.com>
+" Last Change:		2022 Jul 20
 
 " Please check :help html.vim for some comments and a description of the options
 
@@ -23,6 +20,9 @@
 
 syntax spell toplevel
 
+syn include @htmlXml syntax/xml.vim
+unlet b:current_syntax
+
 syn case ignore
 
 " mark illegal characters
@@ -30,13 +30,13 @@
 
 
 " tags
-syn region  htmlString   contained start=+"+ end=+"+ contains=htmlSpecialChar,javaScriptExpression,@htmlPreproc
-syn region  htmlString   contained start=+'+ end=+'+ contains=htmlSpecialChar,javaScriptExpression,@htmlPreproc
-syn match   htmlValue    contained "=[\t ]*[^'" \t>][^ \t>]*"hs=s+1   contains=javaScriptExpression,@htmlPreproc
-syn region  htmlEndTag             start=+</+      end=+>+ contains=htmlTagN,htmlTagError
-syn region  htmlTag                start=+<[^/]+   end=+>+ fold contains=htmlTagN,htmlString,htmlArg,htmlValue,htmlTagError,htmlEvent,htmlCssDefinition,@htmlPreproc,@htmlArgCluster
-syn match   htmlTagN     contained +<\s*[-a-zA-Z0-9]\++hs=s+1 contains=htmlTagName,htmlSpecialTagName,@htmlTagNameCluster
-syn match   htmlTagN     contained +</\s*[-a-zA-Z0-9]\++hs=s+2 contains=htmlTagName,htmlSpecialTagName,@htmlTagNameCluster
+syn region  htmlString	 contained start=+"+ end=+"+ contains=htmlSpecialChar,javaScriptExpression,@htmlPreproc
+syn region  htmlString	 contained start=+'+ end=+'+ contains=htmlSpecialChar,javaScriptExpression,@htmlPreproc
+syn match   htmlValue	 contained "=[\t ]*[^'" \t>][^ \t>]*"hs=s+1   contains=javaScriptExpression,@htmlPreproc
+syn region  htmlEndTag		   start=+</+	   end=+>+ contains=htmlTagN,htmlTagError
+syn region  htmlTag		   start=+<[^/]+   end=+>+ fold contains=htmlTagN,htmlString,htmlArg,htmlValue,htmlTagError,htmlEvent,htmlCssDefinition,@htmlPreproc,@htmlArgCluster
+syn match   htmlTagN	 contained +<\s*[-a-zA-Z0-9]\++hs=s+1 contains=htmlTagName,htmlSpecialTagName,@htmlTagNameCluster
+syn match   htmlTagN	 contained +</\s*[-a-zA-Z0-9]\++hs=s+2 contains=htmlTagName,htmlSpecialTagName,@htmlTagNameCluster
 syn match   htmlTagError contained "[^>]<"ms=s+1
 
 
@@ -47,13 +47,13 @@
 syn keyword htmlTagName contained form hr html img
 syn keyword htmlTagName contained input isindex kbd li link map menu
 syn keyword htmlTagName contained meta ol option param pre p samp span
-syn keyword htmlTagName contained select small sub sup
+syn keyword htmlTagName contained select small strike sub sup
 syn keyword htmlTagName contained table td textarea th tr tt ul var xmp
-syn match htmlTagName contained "\<\(b\|i\|u\|h[1-6]\|em\|strong\|head\|body\|title\)\>"
+syn match   htmlTagName contained "\<\%(b\|i\|u\|h[1-6]\|em\|strong\|head\|body\|title\)\>"
 
 " new html 4.0 tags
-syn keyword htmlTagName contained abbr acronym bdo button col label
-syn keyword htmlTagName contained colgroup fieldset iframe ins legend
+syn keyword htmlTagName contained abbr acronym bdo button col colgroup
+syn keyword htmlTagName contained del fieldset iframe ins label legend
 syn keyword htmlTagName contained object optgroup q s tbody tfoot thead
 
 " new html 5 tags
@@ -65,6 +65,15 @@
 syn keyword htmlTagName contained slot source summary template time track
 syn keyword htmlTagName contained video wbr
 
+" svg and math tags
+syn keyword htmlMathTagName contained math
+syn keyword htmlSvgTagName  contained svg
+
+syn region  htmlMath start="<math>" end="</math>" contains=@htmlXml transparent keepend
+syn region  htmlSvg  start="<svg>"  end="</svg>"  contains=@htmlXml transparent keepend
+
+syn cluster xmlTagHook	add=htmlMathTagName,htmlSvgTagName
+
 " legal arg names
 syn keyword htmlArg contained action
 syn keyword htmlArg contained align alink alt archive background bgcolor
@@ -77,7 +86,7 @@
 syn keyword htmlArg contained rel rev rows rowspan scrolling selected shape
 syn keyword htmlArg contained size src start target text type url
 syn keyword htmlArg contained usemap ismap valign value vlink vspace width wrap
-syn match   htmlArg contained "\<\(http-equiv\|href\|title\)="me=e-1
+syn match   htmlArg contained "\<\%(http-equiv\|href\|title\)="me=e-1
 
 " aria attributes
 exe 'syn match htmlArg contained "\<aria-\%(' . join([
@@ -95,15 +104,15 @@
 " Netscape extensions
 syn keyword htmlTagName contained frame noframes frameset nobr blink
 syn keyword htmlTagName contained layer ilayer nolayer spacer
-syn keyword htmlArg     contained frameborder noresize pagex pagey above below
-syn keyword htmlArg     contained left top visibility clip id noshade
-syn match   htmlArg     contained "\<z-index\>"
+syn keyword htmlArg	contained frameborder noresize pagex pagey above below
+syn keyword htmlArg	contained left top visibility clip id noshade
+syn match   htmlArg	contained "\<z-index\>"
 
 " Microsoft extensions
 syn keyword htmlTagName contained marquee
 
 " html 4.0 arg names
-syn match   htmlArg contained "\<\(accept-charset\|label\)\>"
+syn match   htmlArg contained "\<\%(accept-charset\|label\)\>"
 syn keyword htmlArg contained abbr accept accesskey axis char charoff charset
 syn keyword htmlArg contained cite classid codetype compact data datetime
 syn keyword htmlArg contained declare defer dir disabled for frame
@@ -113,51 +122,57 @@
 syn keyword htmlArg contained summary tabindex valuetype version
 
 " html 5 arg names
-syn keyword htmlArg contained allowfullscreen async autocomplete autofocus
-syn keyword htmlArg contained autoplay challenge contenteditable contextmenu
-syn keyword htmlArg contained controls crossorigin default dirname download
-syn keyword htmlArg contained draggable dropzone form formaction formenctype
-syn keyword htmlArg contained formmethod formnovalidate formtarget hidden
-syn keyword htmlArg contained high icon inputmode keytype kind list loop low
-syn keyword htmlArg contained max min minlength muted nonce novalidate open
-syn keyword htmlArg contained optimum pattern placeholder poster preload
-syn keyword htmlArg contained radiogroup required reversed sandbox spellcheck
-syn keyword htmlArg contained sizes srcset srcdoc srclang step title translate
-syn keyword htmlArg contained typemustmatch
+syn keyword htmlArg contained allow autocapitalize as blocking decoding
+syn keyword htmlArg contained enterkeyhint imagesizes imagesrcset inert
+syn keyword htmlArg contained integrity is itemid itemprop itemref itemscope
+syn keyword htmlArg contained itemtype loading nomodule ping playsinline
+syn keyword htmlArg contained referrerpolicy slot allowfullscreen async
+syn keyword htmlArg contained autocomplete autofocus autoplay challenge
+syn keyword htmlArg contained contenteditable contextmenu controls crossorigin
+syn keyword htmlArg contained default dirname download draggable dropzone form
+syn keyword htmlArg contained formaction formenctype formmethod formnovalidate
+syn keyword htmlArg contained formtarget hidden high icon inputmode keytype
+syn keyword htmlArg contained kind list loop low max min minlength muted nonce
+syn keyword htmlArg contained novalidate open optimum pattern placeholder
+syn keyword htmlArg contained poster preload radiogroup required reversed
+syn keyword htmlArg contained sandbox spellcheck sizes srcset srcdoc srclang
+syn keyword htmlArg contained step title translate typemustmatch
+syn match   htmlArg contained "\<data-\h\%(\w\|[-.]\)*\%(\_s*=\)\@="
 
 " special characters
 syn match htmlSpecialChar "&#\=[0-9A-Za-z]\{1,8};"
 
 " Comments (the real ones or the old netscape ones)
 if exists("html_wrong_comments")
-  syn region htmlComment        start=+<!--+    end=+--\s*>+    contains=@Spell
+  syn region htmlComment	start=+<!--+	end=+--\s*>+	contains=@Spell
 else
   " The HTML 5.2 syntax 8.2.4.41: bogus comment is parser error; browser skips until next &gt
-  syn region htmlComment        start=+<!+      end=+>+         contains=htmlCommentError keepend
+  syn region htmlComment	start=+<!+	end=+>+		contains=htmlCommentError keepend
   " Idem 8.2.4.42,51: Comment starts with <!-- and ends with -->
   " Idem 8.2.4.43,44: Except <!--> and <!---> are parser errors
   " Idem 8.2.4.52: dash-dash-bang (--!>) is error ignored by parser, also closes comment
-  syn region htmlComment matchgroup=htmlComment start=+<!--\%(-\?>\)\@!+        end=+--!\?>+    contains=htmlCommentNested,@htmlPreProc,@Spell keepend
+  syn region htmlComment matchgroup=htmlComment start=+<!--\%(-\?>\)\@!+	end=+--!\?>+	contains=htmlCommentNested,@htmlPreProc,@Spell keepend
   " Idem 8.2.4.49: nested comment is parser error, except <!--> is all right
   syn match htmlCommentNested contained "<!-->\@!"
   syn match htmlCommentError  contained "[^><!]"
 endif
-syn region htmlComment  start=+<!DOCTYPE+       end=+>+ keepend
+syn region htmlComment	start=+<!DOCTYPE+	end=+>+ keepend
 
 " server-parsed commands
 syn region htmlPreProc start=+<!--#+ end=+-->+ contains=htmlPreStmt,htmlPreError,htmlPreAttr
-syn match htmlPreStmt contained "<!--#\(config\|echo\|exec\|fsize\|flastmod\|include\|printenv\|set\|if\|elif\|else\|endif\|geoguide\)\>"
+syn match htmlPreStmt contained "<!--#\%(config\|echo\|exec\|fsize\|flastmod\|include\|printenv\|set\|if\|elif\|else\|endif\|geoguide\)\>"
 syn match htmlPreError contained "<!--#\S*"ms=s+4
 syn match htmlPreAttr contained "\w\+=[^"]\S\+" contains=htmlPreProcAttrError,htmlPreProcAttrName
 syn region htmlPreAttr contained start=+\w\+="+ skip=+\\\\\|\\"+ end=+"+ contains=htmlPreProcAttrName keepend
 syn match htmlPreProcAttrError contained "\w\+="he=e-1
-syn match htmlPreProcAttrName contained "\(expr\|errmsg\|sizefmt\|timefmt\|var\|cgi\|cmd\|file\|virtual\|value\)="he=e-1
+syn match htmlPreProcAttrName contained "\%(expr\|errmsg\|sizefmt\|timefmt\|var\|cgi\|cmd\|file\|virtual\|value\)="he=e-1
 
 if !exists("html_no_rendering")
   " rendering
   syn cluster htmlTop contains=@Spell,htmlTag,htmlEndTag,htmlSpecialChar,htmlPreProc,htmlComment,htmlLink,javaScript,@htmlPreproc
 
   syn region htmlStrike start="<del\>" end="</del\_s*>"me=s-1 contains=@htmlTop
+  syn region htmlStrike start="<s\>" end="</s\_s*>"me=s-1 contains=@htmlTop
   syn region htmlStrike start="<strike\>" end="</strike\_s*>"me=s-1 contains=@htmlTop
 
   syn region htmlBold start="<b\>" end="</b\_s*>"me=s-1 contains=@htmlTop,htmlBoldUnderline,htmlBoldItalic
@@ -200,26 +215,26 @@
   syn region htmlTitle start="<title\>" end="</title\_s*>"me=s-1 contains=htmlTag,htmlEndTag,htmlSpecialChar,htmlPreProc,htmlComment,javaScript,@htmlPreproc
 endif
 
-syn keyword htmlTagName         contained noscript
-syn keyword htmlSpecialTagName  contained script style
+syn keyword htmlTagName		contained noscript
+syn keyword htmlSpecialTagName	contained script style
 if main_syntax != 'java' || exists("java_javascript")
   " JAVA SCRIPT
   syn include @htmlJavaScript syntax/javascript.vim
   unlet b:current_syntax
   syn region  javaScript start=+<script\_[^>]*>+ keepend end=+</script\_[^>]*>+me=s-1 contains=@htmlJavaScript,htmlCssStyleComment,htmlScriptTag,@htmlPreproc
-  syn region  htmlScriptTag     contained start=+<script+ end=+>+ fold contains=htmlTagN,htmlString,htmlArg,htmlValue,htmlTagError,htmlEvent
+  syn region  htmlScriptTag	contained start=+<script+ end=+>+ fold contains=htmlTagN,htmlString,htmlArg,htmlValue,htmlTagError,htmlEvent
   hi def link htmlScriptTag htmlTag
 
   " html events (i.e. arguments that include javascript commands)
   if exists("html_extended_events")
-    syn region htmlEvent        contained start=+\<on\a\+\s*=[\t ]*'+ end=+'+ contains=htmlEventSQ
-    syn region htmlEvent        contained start=+\<on\a\+\s*=[\t ]*"+ end=+"+ contains=htmlEventDQ
+    syn region htmlEvent	contained start=+\<on\a\+\s*=[\t ]*'+ end=+'+ contains=htmlEventSQ
+    syn region htmlEvent	contained start=+\<on\a\+\s*=[\t ]*"+ end=+"+ contains=htmlEventDQ
   else
-    syn region htmlEvent        contained start=+\<on\a\+\s*=[\t ]*'+ end=+'+ keepend contains=htmlEventSQ
-    syn region htmlEvent        contained start=+\<on\a\+\s*=[\t ]*"+ end=+"+ keepend contains=htmlEventDQ
+    syn region htmlEvent	contained start=+\<on\a\+\s*=[\t ]*'+ end=+'+ keepend contains=htmlEventSQ
+    syn region htmlEvent	contained start=+\<on\a\+\s*=[\t ]*"+ end=+"+ keepend contains=htmlEventDQ
   endif
-  syn region htmlEventSQ        contained start=+'+ms=s+1 end=+'+me=s-1 contains=@htmlJavaScript
-  syn region htmlEventDQ        contained start=+"+ms=s+1 end=+"+me=s-1 contains=@htmlJavaScript
+  syn region htmlEventSQ	contained start=+'+ms=s+1 end=+'+me=s-1 contains=@htmlJavaScript
+  syn region htmlEventDQ	contained start=+"+ms=s+1 end=+"+me=s-1 contains=@htmlJavaScript
   hi def link htmlEventSQ htmlEvent
   hi def link htmlEventDQ htmlEvent
 
@@ -234,15 +249,15 @@
   syn region  javaScript start=+<script \_[^>]*language *=\_[^>]*vbscript\_[^>]*>+ keepend end=+</script\_[^>]*>+me=s-1 contains=@htmlVbScript,htmlCssStyleComment,htmlScriptTag,@htmlPreproc
 endif
 
-syn cluster htmlJavaScript      add=@htmlPreproc
+syn cluster htmlJavaScript	add=@htmlPreproc
 
 if main_syntax != 'java' || exists("java_css")
   " embedded style sheets
-  syn keyword htmlArg           contained media
+  syn keyword htmlArg		contained media
   syn include @htmlCss syntax/css.vim
   unlet b:current_syntax
   syn region cssStyle start=+<style+ keepend end=+</style>+ contains=@htmlCss,htmlTag,htmlEndTag,htmlCssStyleComment,@htmlPreproc
-  syn match htmlCssStyleComment contained "\(<!--\|-->\)"
+  syn match htmlCssStyleComment contained "\%(<!--\|-->\)"
   syn region htmlCssDefinition matchgroup=htmlArg start='style="' keepend matchgroup=htmlString end='"' contains=css.*Attr,css.*Prop,cssComment,cssLength,cssColor,cssURL,cssImportant,cssError,cssString,@htmlPreproc
   hi def link htmlStyleArg htmlString
 endif
@@ -258,68 +273,70 @@
 endif
 
 " The default highlighting.
-hi def link htmlTag                     Function
-hi def link htmlEndTag                  Identifier
-hi def link htmlArg                     Type
-hi def link htmlTagName                 htmlStatement
-hi def link htmlSpecialTagName          Exception
-hi def link htmlValue                   String
-hi def link htmlSpecialChar             Special
+hi def link htmlTag			Function
+hi def link htmlEndTag			Identifier
+hi def link htmlArg			Type
+hi def link htmlTagName			htmlStatement
+hi def link htmlSpecialTagName		Exception
+hi def link htmlMathTagName		htmlTagName
+hi def link htmlSvgTagName		htmlTagName
+hi def link htmlValue			String
+hi def link htmlSpecialChar		Special
 
 if !exists("html_no_rendering")
-  hi def link htmlH1                      Title
-  hi def link htmlH2                      htmlH1
-  hi def link htmlH3                      htmlH2
-  hi def link htmlH4                      htmlH3
-  hi def link htmlH5                      htmlH4
-  hi def link htmlH6                      htmlH5
-  hi def link htmlHead                    PreProc
-  hi def link htmlTitle                   Title
-  hi def link htmlBoldItalicUnderline     htmlBoldUnderlineItalic
-  hi def link htmlUnderlineBold           htmlBoldUnderline
-  hi def link htmlUnderlineItalicBold     htmlBoldUnderlineItalic
-  hi def link htmlUnderlineBoldItalic     htmlBoldUnderlineItalic
-  hi def link htmlItalicUnderline         htmlUnderlineItalic
-  hi def link htmlItalicBold              htmlBoldItalic
-  hi def link htmlItalicBoldUnderline     htmlBoldUnderlineItalic
-  hi def link htmlItalicUnderlineBold     htmlBoldUnderlineItalic
-  hi def link htmlLink                    Underlined
-  hi def link htmlLeadingSpace            None
+  hi def link htmlH1			  Title
+  hi def link htmlH2			  htmlH1
+  hi def link htmlH3			  htmlH2
+  hi def link htmlH4			  htmlH3
+  hi def link htmlH5			  htmlH4
+  hi def link htmlH6			  htmlH5
+  hi def link htmlHead			  PreProc
+  hi def link htmlTitle			  Title
+  hi def link htmlBoldItalicUnderline	  htmlBoldUnderlineItalic
+  hi def link htmlUnderlineBold		  htmlBoldUnderline
+  hi def link htmlUnderlineItalicBold	  htmlBoldUnderlineItalic
+  hi def link htmlUnderlineBoldItalic	  htmlBoldUnderlineItalic
+  hi def link htmlItalicUnderline	  htmlUnderlineItalic
+  hi def link htmlItalicBold		  htmlBoldItalic
+  hi def link htmlItalicBoldUnderline	  htmlBoldUnderlineItalic
+  hi def link htmlItalicUnderlineBold	  htmlBoldUnderlineItalic
+  hi def link htmlLink			  Underlined
+  hi def link htmlLeadingSpace		  None
   if !exists("html_my_rendering")
-    hi def htmlBold                term=bold cterm=bold gui=bold
-    hi def htmlBoldUnderline       term=bold,underline cterm=bold,underline gui=bold,underline
-    hi def htmlBoldItalic          term=bold,italic cterm=bold,italic gui=bold,italic
+    hi def htmlBold		   term=bold cterm=bold gui=bold
+    hi def htmlBoldUnderline	   term=bold,underline cterm=bold,underline gui=bold,underline
+    hi def htmlBoldItalic	   term=bold,italic cterm=bold,italic gui=bold,italic
     hi def htmlBoldUnderlineItalic term=bold,italic,underline cterm=bold,italic,underline gui=bold,italic,underline
-    hi def htmlUnderline           term=underline cterm=underline gui=underline
-    hi def htmlUnderlineItalic     term=italic,underline cterm=italic,underline gui=italic,underline
-    hi def htmlItalic              term=italic cterm=italic gui=italic
+    hi def htmlUnderline	   term=underline cterm=underline gui=underline
+    hi def htmlUnderlineItalic	   term=italic,underline cterm=italic,underline gui=italic,underline
+    hi def htmlItalic		   term=italic cterm=italic gui=italic
     if v:version > 800 || v:version == 800 && has("patch1038")
-        hi def htmlStrike              term=strikethrough cterm=strikethrough gui=strikethrough
+	hi def htmlStrike	       term=strikethrough cterm=strikethrough gui=strikethrough
     else
-        hi def htmlStrike              term=underline cterm=underline gui=underline
+	hi def htmlStrike	       term=underline cterm=underline gui=underline
     endif
   endif
 endif
 
-hi def link htmlPreStmt            PreProc
-hi def link htmlPreError           Error
-hi def link htmlPreProc            PreProc
-hi def link htmlPreAttr            String
+hi def link htmlPreStmt		   PreProc
+hi def link htmlPreError	   Error
+hi def link htmlPreProc		   PreProc
+hi def link htmlPreAttr		   String
 hi def link htmlPreProcAttrName    PreProc
 hi def link htmlPreProcAttrError   Error
-hi def link htmlString             String
-hi def link htmlStatement          Statement
-hi def link htmlComment            Comment
-hi def link htmlCommentNested      htmlError
-hi def link htmlCommentError       htmlError
-hi def link htmlTagError           htmlError
-hi def link htmlEvent              javaScript
-hi def link htmlError              Error
+hi def link htmlString		   String
+hi def link htmlStatement	   Statement
+hi def link htmlComment		   Comment
+hi def link htmlCommentNested	   htmlError
+hi def link htmlCommentError	   htmlError
+hi def link htmlTagError	   htmlError
+hi def link htmlEvent		   javaScript
+hi def link htmlError		   Error
 
-hi def link javaScript             Special
+hi def link javaScript		   Special
 hi def link javaScriptExpression   javaScript
 hi def link htmlCssStyleComment    Comment
-hi def link htmlCssDefinition      Special
+hi def link htmlCssDefinition	   Special
 
 let b:current_syntax = "html"