lets try again...

sources_non_forked/vim-less/syntax/less.vim

@@ -0,0 +1,44 @@
+if exists("b:current_syntax")
+  finish
+endif
+
+runtime! syntax/css.vim
+runtime! after/syntax/css.vim
+" load files from vim-css3-syntax plugin (https://github.com/hail2u/vim-css3-syntax)
+runtime! after/syntax/css/*.vim
+
+syn case ignore
+
+syn region lessDefinition transparent matchgroup=cssBraces start='{' end='}' contains=css.*Attr,css.*Prop,cssComment,cssValue.*,cssColor,cssTagName,cssPseudoClass,cssUrl,cssImportant,cssError,cssStringQ,cssStringQQ,cssFunction,cssUnicodeEscape,lessDefinition,lessComment,lessClassChar,lessVariable,lessMixinChar,lessAmpersandChar,lessFunction,@cssColors fold
+
+syn match lessVariable "@[[:alnum:]_-]\+" contained 
+syn match lessVariable "@[[:alnum:]_-]\+" nextgroup=lessVariableAssignment skipwhite
+syn match lessVariableAssignment ":" contained nextgroup=lessVariableValue skipwhite
+syn match lessVariableValue ".*;"me=e-1 contained contains=lessVariable,lessOperator,lessDefault,cssValue.*,@cssColors "me=e-1 means that the last char of the pattern is not highlighted
+
+syn match lessOperator "+" contained
+syn match lessOperator "-" contained
+syn match lessOperator "/" contained
+syn match lessOperator "*" contained
+
+syn match lessDefault "!default" contained
+
+syn match lessMixinChar "\.[[:alnum:]_-]\@=" contained nextgroup=lessClass
+syn match lessAmpersandChar "&" contained nextgroup=lessClass,cssPseudoClass
+syn match lessClass "[[:alnum:]_-]\+" contained
+
+syn keyword lessFunction lighten darken saturate desaturate fadein fadeout spin hue saturation lightness containedin=cssDefinition contained 
+
+syn match lessComment "//.*$" contains=@Spell
+
+hi def link lessVariable Special
+hi def link lessVariableValue Constant
+hi def link lessDefault Special
+hi def link lessComment Comment
+hi def link lessFunction Function
+hi def link lessMixinChar Special
+hi def link lessAmpersandChar Special
+hi def link lessClass PreProc
+
+let b:current_syntax = "less"
+