diff --git a/runtime/syntax/dot.vim b/runtime/syntax/dot.vim
index 0fdd6ea..68a0f57 100644
--- a/runtime/syntax/dot.vim
+++ b/runtime/syntax/dot.vim
@@ -1,16 +1,22 @@
-" Vim syntax file
 " Language:     Dot
 " Filenames:    *.dot
 " Maintainer:   Markus Mottl  <markus.mottl@gmail.com>
 " URL:          http://www.ocaml.info/vim/syntax/dot.vim
-" Last Change:  2011 May 17 - improved identifier matching + two new keywords
+" Last Change:  2021 Mar 24 - better attr + escape string matching, new keywords (Farbod Salamat-Zadeh)
+"               2011 May 17 - improved identifier matching + two new keywords
 "               2001 May 04 - initial version
 
-" quit when a syntax file was already loaded
-if exists("b:current_syntax")
+" For version 5.x: Clear all syntax items
+" For version 6.x: Quit when a syntax file was already loaded
+if version < 600
+  syntax clear
+elseif exists("b:current_syntax")
   finish
 endif
 
+let s:keepcpo = &cpo
+set cpo&vim
+
 " Errors
 syn match    dotParErr     ")"
 syn match    dotBrackErr   "]"
@@ -29,39 +35,43 @@
 " Strings
 syn region   dotString    start=+"+ skip=+\\\\\|\\"+ end=+"+
 
+" Escape strings
+syn match    dotEscString /\v\\(N|G|E|T|H|L)/ containedin=dotString
+syn match    dotEscString /\v\\(n|l|r)/       containedin=dotString
+
 " General keywords
-syn keyword  dotKeyword  digraph node edge subgraph
+syn keyword  dotKeyword graph digraph subgraph node edge strict
 
-" Graph attributes
-syn keyword  dotType center layers margin mclimit name nodesep nslimit
-syn keyword  dotType ordering page pagedir rank rankdir ranksep ratio
-syn keyword  dotType rotate size
-
-" Node attributes
-syn keyword  dotType distortion fillcolor fontcolor fontname fontsize
-syn keyword  dotType height layer orientation peripheries regular
-syn keyword  dotType shape shapefile sides skew width
-
-" Edge attributes
-syn keyword  dotType arrowhead arrowsize arrowtail constraint decorateP
-syn keyword  dotType dir headclip headlabel headport labelangle labeldistance
-syn keyword  dotType labelfontcolor labelfontname labelfontsize
-syn keyword  dotType minlen port_label_distance samehead sametail
-syn keyword  dotType tailclip taillabel tailport weight
-
-" Shared attributes (graphs, nodes, edges)
-syn keyword  dotType color
-
-" Shared attributes (graphs and edges)
-syn keyword  dotType bgcolor label URL
-
-" Shared attributes (nodes and edges)
-syn keyword  dotType fontcolor fontname fontsize layer style
+" Node, edge and graph attributes
+syn keyword  dotType _background area arrowhead arrowsize arrowtail bb bgcolor
+      \ center charset class clusterrank color colorscheme comment compound
+      \ concentrate constraint Damping decorate defaultdist dim dimen dir
+      \ diredgeconstraints distortion dpi edgehref edgetarget edgetooltip
+      \ edgeURL epsilon esep fillcolor fixedsize fontcolor fontname fontnames
+      \ fontpath fontsize forcelabels gradientangle group head_lp headclip
+      \ headhref headlabel headport headtarget headtooltip headURL height href
+      \ id image imagepath imagepos imagescale inputscale K label label_scheme
+      \ labelangle labeldistance labelfloat labelfontcolor labelfontname
+      \ labelfontsize labelhref labeljust labelloc labeltarget labeltooltip
+      \ labelURL landscape layer layerlistsep layers layerselect layersep 
+      \ layout len levels levelsgap lhead lheight lp ltail lwidth margin
+      \ maxiter mclimit mindist minlen mode model mosek newrank nodesep 
+      \ nojustify normalize notranslate nslimit nslimit1 ordering orientation
+      \ outputorder overlap overlap_scaling overlap_shrink pack packmode pad
+      \ page pagedir pencolor penwidth peripheries pin pos quadtree quantum
+      \ rank rankdir ranksep ratio rects regular remincross repulsiveforce
+      \ resolution root rotate rotation samehead sametail samplepoints scale
+      \ searchsize sep shape shapefile showboxes sides size skew smoothing
+      \ sortv splines start style stylesheet tail_lp tailclip tailhref 
+      \ taillabel tailport tailtarget tailtooltip tailURL target tooltip
+      \ truecolor URL vertices viewport voro_margin weight width xdotversion 
+      \ xlabel xlp z
 
 " Special chars
 syn match    dotKeyChar  "="
 syn match    dotKeyChar  ";"
 syn match    dotKeyChar  "->"
+syn match    dotKeyChar  "--"
 
 " Identifier
 syn match    dotIdentifier /\<\w\+\(:\w\+\)\?\>/
@@ -71,27 +81,41 @@
 syn sync maxlines=500
 
 " Define the default highlighting.
-" Only when an item doesn't have highlighting yet
+" For version 5.7 and earlier: only when not done already
+" For version 5.8 and later: only when an item doesn't have highlighting yet
+if version >= 508 || !exists("did_dot_syntax_inits")
+  if version < 508
+    let did_dot_syntax_inits = 1
+    command -nargs=+ HiLink hi link <args>
+  else
+    command -nargs=+ HiLink hi def link <args>
+  endif
 
-hi def link dotParErr	 Error
-hi def link dotBraceErr	 Error
-hi def link dotBrackErr	 Error
+  HiLink dotParErr	 Error
+  HiLink dotBraceErr	 Error
+  HiLink dotBrackErr	 Error
 
-hi def link dotComment	 Comment
-hi def link dotTodo	 Todo
+  HiLink dotComment	 Comment
+  HiLink dotTodo	 Todo
 
-hi def link dotParEncl	 Keyword
-hi def link dotBrackEncl	 Keyword
-hi def link dotBraceEncl	 Keyword
+  HiLink dotParEncl	 Keyword
+  HiLink dotBrackEncl	 Keyword
+  HiLink dotBraceEncl	 Keyword
 
-hi def link dotKeyword	 Keyword
-hi def link dotType	 Type
-hi def link dotKeyChar	 Keyword
+  HiLink dotKeyword	 Keyword
+  HiLink dotType	 Type
+  HiLink dotKeyChar	 Keyword
 
-hi def link dotString	 String
-hi def link dotIdentifier	 Identifier
+  HiLink dotString	 String
+  HiLink dotEscString	 Keyword
+  HiLink dotIdentifier	 Identifier
 
+  delcommand HiLink
+endif
 
 let b:current_syntax = "dot"
 
+let &cpo = s:keepcpo
+unlet s:keepcpo
+
 " vim: ts=8
diff --git a/runtime/syntax/groff.vim b/runtime/syntax/groff.vim
index 2cc7ccf..c076c8d 100644
--- a/runtime/syntax/groff.vim
+++ b/runtime/syntax/groff.vim
@@ -1,7 +1,7 @@
 " VIM syntax file
 " Language:	groff
-" Maintainer:	Alejandro López-Valencia <dradul@yahoo.com>
-" URL:		http://dradul.tripod.com/vim
+" Maintainer:	John Marshall <jmarshall@hey.com>
+" Previous Maintainer:	Pedro Alejandro López-Valencia <palopezv@gmail.com>
 " Last Change:	2003-05-08-12:41:13 GMT-5.
 
 " This uses the nroff.vim syntax file.
diff --git a/runtime/syntax/javascript.vim b/runtime/syntax/javascript.vim
index 8a5e10b..1ab1c2d 100644
--- a/runtime/syntax/javascript.vim
+++ b/runtime/syntax/javascript.vim
@@ -7,7 +7,7 @@
 "		(ss) repaired several quoting and grouping glitches
 "		(ss) fixed regex parsing issue with multiple qualifiers [gi]
 "		(ss) additional factoring of keywords, globals, and members
-" Last Change:	2020 May 14
+" Last Change:	2021 Mar 30
 " 		2013 Jun 12: adjusted javaScriptRegexpString (Kevin Locke)
 " 		2018 Apr 14: adjusted javaScriptRegexpString (LongJohnCoder)
 
@@ -41,6 +41,7 @@
 
 syn match   javaScriptSpecialCharacter "'\\.'"
 syn match   javaScriptNumber	       "-\=\<\d\+L\=\>\|0[xX][0-9a-fA-F]\+\>"
+syn match   javaScriptNumber	       "-\=\<\d\+\%(_\d\+\)*\>"
 syn region  javaScriptRegexpString     start=+[,(=+]\s*/[^/*]+ms=e-1,me=e-1 skip=+\\\\\|\\/+ end=+/[gimuys]\{0,2\}\s*$+ end=+/[gimuys]\{0,2\}\s*[+;.,)\]}]+me=e-1 end=+/[gimuys]\{0,2\}\s\+\/+me=e-1 contains=@htmlPreproc,javaScriptComment oneline
 
 syn keyword javaScriptConditional	if else switch
diff --git a/runtime/syntax/nroff.vim b/runtime/syntax/nroff.vim
index 04532e0..5667042 100644
--- a/runtime/syntax/nroff.vim
+++ b/runtime/syntax/nroff.vim
@@ -1,16 +1,9 @@
 " VIM syntax file
 " Language:	nroff/groff
-" Maintainer:	Pedro Alejandro López-Valencia <palopezv@gmail.com>
-" URL:		http://vorbote.wordpress.com/
-" Last Change:	2012 Feb 2
-"
-" {{{1 Acknowledgements
-"
-" ACKNOWLEDGEMENTS:
-"
-" My thanks to Jérôme Plût <Jerome.Plut@ens.fr>, who was the
-" creator and maintainer of this syntax file for several years.
-" May I be as good at it as he has been.
+" Maintainer:	John Marshall <jmarshall@hey.com>
+" Previous Maintainer:	Pedro Alejandro López-Valencia <palopezv@gmail.com>
+" Previous Maintainer:	Jérôme Plût <Jerome.Plut@ens.fr>
+" Last Change:	2021 Mar 28
 "
 " {{{1 Todo
 "
@@ -31,6 +24,13 @@
 let s:cpo_save = &cpo
 set cpo&vim
 
+if exists("nroff_is_groff")
+	let b:nroff_is_groff = 1
+endif
+
+syn spell toplevel
+syn case match
+
 "
 " {{{1 plugin settings...
 "
@@ -48,7 +48,7 @@
 "
 setlocal paragraphs+=XP
 "
-" {{{2 Activate navigation to preporcessor sections.
+" {{{2 Activate navigation to preprocessor sections.
 "
 if exists("b:preprocs_as_sections")
 	setlocal sections=EQTSPS[\ G1GS
@@ -169,9 +169,9 @@
 " <jp />
 
 syn region nroffEquation start=/^\.\s*EQ\>/ end=/^\.\s*EN\>/
-syn region nroffTable start=/^\.\s*TS\>/ end=/^\.\s*TE\>/
+syn region nroffTable start=/^\.\s*TS\>/ end=/^\.\s*TE\>/ contains=@Spell
 syn region nroffPicture start=/^\.\s*PS\>/ end=/^\.\s*PE\>/
-syn region nroffRefer start=/^\.\s*\[\>/ end=/^\.\s*\]\>/
+syn region nroffRefer start=/^\.\s*\[\>/ end=/^\.\s*\]\>/ contains=@Spell
 syn region nroffGrap start=/^\.\s*G1\>/ end=/^\.\s*G2\>/
 syn region nroffGremlin start=/^\.\s*GS\>/ end=/^\.\s*GE|GF\>/
 
@@ -179,11 +179,11 @@
 " ------------------------------------------------------------
 
 syn region nroffIgnore start=/^[.']\s*ig/ end=/^['.]\s*\./
-syn match nroffComment /\(^[.']\s*\)\=\\".*/ contains=nroffTodo
-syn match nroffComment /^'''.*/  contains=nroffTodo
+syn match nroffComment /\(^[.']\s*\)\=\\".*/ contains=nroffTodo,@Spell
+syn match nroffComment /^'''.*/  contains=nroffTodo,@Spell
 
 if exists("b:nroff_is_groff")
-	syn match nroffComment "\\#.*$" contains=nroffTodo
+	syn match nroffComment "\\#.*$" contains=nroffTodo,@Spell
 endif
 
 syn keyword nroffTodo TODO XXX FIXME contained
@@ -198,7 +198,7 @@
 "
 
 hi def link nroffEscChar nroffSpecialChar
-hi def link nroffEscCharAr nroffSpecialChar
+hi def link nroffEscCharArg nroffSpecialChar
 hi def link nroffSpecialChar SpecialChar
 hi def link nroffSpace Delimiter
 
@@ -211,7 +211,7 @@
 hi def link nroffEscRegPar nroffEscape
 hi def link nroffEscArg nroffEscape
 hi def link nroffSize nroffEscape
-hi def link nroffEscape Preproc
+hi def link nroffEscape PreProc
 
 hi def link nroffIgnore Comment
 hi def link nroffComment Comment
diff --git a/runtime/syntax/sshconfig.vim b/runtime/syntax/sshconfig.vim
index d0752ae..ae3c7dd 100644
--- a/runtime/syntax/sshconfig.vim
+++ b/runtime/syntax/sshconfig.vim
@@ -1,14 +1,15 @@
 " Vim syntax file
 " Language:	OpenSSH client configuration file (ssh_config)
 " Author:	David Necas (Yeti)
-" Maintainer:	Dominik Fischer <d dot f dot fischer at web dot de>
+" Maintainer:	Jakub Jelen <jakuje at gmail dot com>
+" Previous Maintainer:	Dominik Fischer <d dot f dot fischer at web dot de>
 " Contributor:  Leonard Ehrenfried <leonard.ehrenfried@web.de>
 " Contributor:  Karsten Hopp <karsten@redhat.com>
 " Contributor:  Dean, Adam Kenneth <adam.ken.dean@hpe.com>
-" Last Change:	2020 Feb 12
+" Last Change:	2021 Mar 29
 "		Added RemoteCommand from pull request #4809
 "		Included additional keywords from Martin.
-" SSH Version:	7.4p1
+" SSH Version:	8.5p1
 "
 
 " Setup
@@ -174,6 +175,7 @@
 syn keyword sshconfigKeyword HostKeyAlias
 syn keyword sshconfigKeyword HostName
 syn keyword sshconfigKeyword HostbasedAuthentication
+syn keyword sshconfigKeyword HostbasedAcceptedAlgorithms
 syn keyword sshconfigKeyword HostbasedKeyTypes
 syn keyword sshconfigKeyword IPQoS
 syn keyword sshconfigKeyword IdentitiesOnly
@@ -185,9 +187,11 @@
 syn keyword sshconfigKeyword KbdInteractiveAuthentication
 syn keyword sshconfigKeyword KbdInteractiveDevices
 syn keyword sshconfigKeyword KexAlgorithms
+syn keyword sshconfigKeyword KnownHostsCommand
 syn keyword sshconfigKeyword LocalCommand
 syn keyword sshconfigKeyword LocalForward
 syn keyword sshconfigKeyword LogLevel
+syn keyword sshconfigKeyword LogVerbose
 syn keyword sshconfigKeyword MACs
 syn keyword sshconfigKeyword Match
 syn keyword sshconfigKeyword NoHostAuthenticationForLocalhost
@@ -195,11 +199,13 @@
 syn keyword sshconfigKeyword PKCS11Provider
 syn keyword sshconfigKeyword PasswordAuthentication
 syn keyword sshconfigKeyword PermitLocalCommand
+syn keyword sshconfigKeyword PermitRemoteOpen
 syn keyword sshconfigKeyword Port
 syn keyword sshconfigKeyword PreferredAuthentications
 syn keyword sshconfigKeyword ProxyCommand
 syn keyword sshconfigKeyword ProxyJump
 syn keyword sshconfigKeyword ProxyUseFDPass
+syn keyword sshconfigKeyword PubkeyAcceptedAlgorithms
 syn keyword sshconfigKeyword PubkeyAcceptedKeyTypes
 syn keyword sshconfigKeyword PubkeyAuthentication
 syn keyword sshconfigKeyword RekeyLimit
diff --git a/runtime/syntax/sshdconfig.vim b/runtime/syntax/sshdconfig.vim
index 8534ff6..6b0d2af 100644
--- a/runtime/syntax/sshdconfig.vim
+++ b/runtime/syntax/sshdconfig.vim
@@ -7,8 +7,8 @@
 " Contributor:  Leonard Ehrenfried <leonard.ehrenfried@web.de>	
 " Contributor:  Karsten Hopp <karsten@redhat.com>
 " Originally:	2009-07-09
-" Last Change:	2020-10-20
-" SSH Version:	8.4p1
+" Last Change:	2021-03-29
+" SSH Version:	8.5p1
 "
 
 " Setup
@@ -195,6 +195,7 @@
 syn keyword sshdconfigKeyword HostKey
 syn keyword sshdconfigKeyword HostKeyAgent
 syn keyword sshdconfigKeyword HostKeyAlgorithms
+syn keyword sshdconfigKeyword HostbasedAcceptedAlgorithms
 syn keyword sshdconfigKeyword HostbasedAcceptedKeyTypes
 syn keyword sshdconfigKeyword HostbasedAuthentication
 syn keyword sshdconfigKeyword HostbasedUsesNameFromPacketOnly
@@ -213,6 +214,7 @@
 syn keyword sshdconfigKeyword KeyRegenerationInterval
 syn keyword sshdconfigKeyword ListenAddress
 syn keyword sshdconfigKeyword LogLevel
+syn keyword sshdconfigKeyword LogVerbose
 syn keyword sshdconfigKeyword LoginGraceTime
 syn keyword sshdconfigKeyword MACs
 syn keyword sshdconfigKeyword Match
@@ -220,6 +222,8 @@
 syn keyword sshdconfigKeyword MaxSessions
 syn keyword sshdconfigKeyword MaxStartups
 syn keyword sshdconfigKeyword PasswordAuthentication
+syn keyword sshdconfigKeyword PerSourceMaxStartups
+syn keyword sshdconfigKeyword PerSourceNetBlockSize
 syn keyword sshdconfigKeyword PermitBlacklistedKeys
 syn keyword sshdconfigKeyword PermitEmptyPasswords
 syn keyword sshdconfigKeyword PermitListen
@@ -234,6 +238,7 @@
 syn keyword sshdconfigKeyword PrintLastLog
 syn keyword sshdconfigKeyword PrintMotd
 syn keyword sshdconfigKeyword Protocol
+syn keyword sshdconfigKeyword PubkeyAcceptedAlgorithms
 syn keyword sshdconfigKeyword PubkeyAcceptedKeyTypes
 syn keyword sshdconfigKeyword PubkeyAuthentication
 syn keyword sshdconfigKeyword PubkeyAuthOptions
diff --git a/runtime/syntax/sudoers.vim b/runtime/syntax/sudoers.vim
index 019b0ad..bf2d337 100644
--- a/runtime/syntax/sudoers.vim
+++ b/runtime/syntax/sudoers.vim
@@ -1,7 +1,8 @@
 " Vim syntax file
 " Language:             sudoers(5) configuration files
+" Maintainer:           Eisuke Kawashima ( e.kawaschima+vim AT gmail.com )
 " Previous Maintainer:  Nikolai Weibull <now@bitwi.se>
-" Latest Revision:      2018-08-18
+" Latest Revision:      2021 Mar 15
 " Recent Changes:	Support for #include and #includedir.
 " 			Added many new options (Samuel D. Leslie)
 
@@ -26,7 +27,7 @@
 syn keyword sudoersTodo               contained TODO FIXME XXX NOTE
 
 syn region  sudoersComment            display oneline start='#' end='$' contains=sudoersTodo
-syn region  sudoersInclude            display oneline start='#\(include\|includedir\)' end='$'
+syn region  sudoersInclude            display oneline start='[#@]\%(include\|includedir\)\>' end='$'
 
 syn keyword sudoersAlias              User_Alias Runas_Alias nextgroup=sudoersUserAlias skipwhite skipnl
 syn keyword sudoersAlias              Host_Alias nextgroup=sudoersHostAlias skipwhite skipnl
@@ -201,7 +202,7 @@
                                   \ shell_noargs
                                   \ stay_setuid
                                   \ sudoedit_checkdir
-                                  \ sudoedit_fellow
+                                  \ sudoedit_follow
                                   \ syslog_pid
                                   \ targetpw
                                   \ tty_tickets