diff --git a/autotests/folding/highlight.rb.fold b/autotests/folding/highlight.rb.fold
--- a/autotests/folding/highlight.rb.fold
+++ b/autotests/folding/highlight.rb.fold
@@ -549,3 +549,25 @@
 :@abc
 :@@abc
 :$abc
+
+# squiggly HEREDOC
+<beginfold id='3'>    <<~</beginfold id='3'>HEREDOC
+      Hello!!
+    <endfold id='3'>HEREDOC</endfold id='3'>
+
+# HEREDOC with backticks
+<beginfold id='3'><<</beginfold id='3'>`HEREDOC`
+    echo "hello"
+<endfold id='3'>HEREDOC</endfold id='3'>
+
+# do not highlight HEREDOC markers after the "class" keyword
+# (singleton class definition) (bug: #358273)
+<beginfold id='1'>class</beginfold id='1'> <<Foo = Object.new
+  attr_accessor :foo
+<endfold id='1'>end</endfold id='1'>
+singleton_class = ( <beginfold id='1'>class</beginfold id='1'> <<foo; self; <endfold id='1'>end</endfold id='1'> )
+
+# highlight regular expressions after ": " (bug: #361875)
+get 'files/:slug/:filename', to: 'files#download', slug: /^[a-z]+$/, filename: <beginfold id='5'>%</beginfold id='5'>r|^[/\s]+$<endfold id='5'>|</endfold id='5'>
+@@hello!: /regexp/
+[]=: <beginfold id='5'>%</beginfold id='5'>r!regexp<endfold id='5'>!</endfold id='5'>
diff --git a/autotests/html/highlight.rb.html b/autotests/html/highlight.rb.html
--- a/autotests/html/highlight.rb.html
+++ b/autotests/html/highlight.rb.html
@@ -555,4 +555,26 @@
 <span style="color:#d40000;">:@abc</span>
 <span style="color:#d40000;">:@@abc</span>
 <span style="color:#d40000;">:$abc</span>
+
+<span style="color:#898887;"># squiggly HEREDOC</span>
+<span style="color:#ff9fec;">    &lt;&lt;~</span><span style="font-weight:bold;">HEREDOC</span>
+<span style="color:#006e28;">      Hello!!</span>
+<span style="color:#006e28;">    </span><span style="font-weight:bold;">HEREDOC</span>
+
+<span style="color:#898887;"># HEREDOC with backticks</span>
+<span style="color:#ff9fec;">&lt;&lt;</span><span style="font-weight:bold;">`HEREDOC`</span>
+<span style="color:#006e28;">    echo &quot;hello&quot;</span>
+<span style="font-weight:bold;">HEREDOC</span>
+
+<span style="color:#898887;"># do not highlight HEREDOC markers after the &quot;class&quot; keyword</span>
+<span style="color:#898887;"># (singleton class definition) (bug: #358273)</span>
+<span style="font-weight:bold;">class</span> <span style="color:#ff9fec;">&lt;&lt;</span><span style="color:#0057ae;">Foo</span> <span style="color:#ff9fec;">=</span> <span style="color:#0057ae;">Object</span><span style="color:#4000a7;">.new</span>
+  <span style="color:#006e28;">attr_accessor</span> <span style="color:#d40000;">:foo</span>
+<span style="font-weight:bold;">end</span>
+singleton_class <span style="color:#ff9fec;">=</span> ( <span style="font-weight:bold;">class</span> <span style="color:#ff9fec;">&lt;&lt;</span>foo; <span style="color:#b08000;">self</span>; <span style="font-weight:bold;">end</span> )
+
+<span style="color:#898887;"># highlight regular expressions after &quot;: &quot; (bug: #361875)</span>
+get <span style="color:#dd4a4a;">'files/:slug/:filename'</span>, <span style="color:#d40000;">to: </span><span style="color:#dd4a4a;">'files#download'</span>, <span style="color:#d40000;">slug: </span><span style="color:#4a5704;">/^[a-z]+$/</span>, <span style="color:#d40000;">filename: </span><span style="color:#006e28;">%r|</span><span style="color:#4a5704;">^[/\s]+$</span><span style="color:#006e28;">|</span>
+<span style="color:#d40000;">@@hello!: </span><span style="color:#4a5704;">/regexp/</span>
+<span style="color:#d40000;">[]=: </span><span style="color:#006e28;">%r!</span><span style="color:#4a5704;">regexp</span><span style="color:#006e28;">!</span>
 </pre></body></html>
diff --git a/autotests/input/highlight.rb b/autotests/input/highlight.rb
--- a/autotests/input/highlight.rb
+++ b/autotests/input/highlight.rb
@@ -549,3 +549,25 @@
 :@abc
 :@@abc
 :$abc
+
+# squiggly HEREDOC
+    <<~HEREDOC
+      Hello!!
+    HEREDOC
+
+# HEREDOC with backticks
+<<`HEREDOC`
+    echo "hello"
+HEREDOC
+
+# do not highlight HEREDOC markers after the "class" keyword
+# (singleton class definition) (bug: #358273)
+class <<Foo = Object.new
+  attr_accessor :foo
+end
+singleton_class = ( class <<foo; self; end )
+
+# highlight regular expressions after ": " (bug: #361875)
+get 'files/:slug/:filename', to: 'files#download', slug: /^[a-z]+$/, filename: %r|^[/\s]+$|
+@@hello!: /regexp/
+[]=: %r!regexp!
diff --git a/autotests/reference/highlight.rb.ref b/autotests/reference/highlight.rb.ref
--- a/autotests/reference/highlight.rb.ref
+++ b/autotests/reference/highlight.rb.ref
@@ -549,3 +549,25 @@
 <Symbol>:@abc</Symbol><br/>
 <Symbol>:@@abc</Symbol><br/>
 <Symbol>:$abc</Symbol><br/>
+<Normal Text></Normal Text><br/>
+<Comment># squiggly HEREDOC</Comment><br/>
+<Operator>    <<~</Operator><Keyword>HEREDOC</Keyword><br/>
+<Here Document>      Hello!!</Here Document><br/>
+<Here Document>    </Here Document><Keyword>HEREDOC</Keyword><br/>
+<Normal Text></Normal Text><br/>
+<Comment># HEREDOC with backticks</Comment><br/>
+<Operator><<</Operator><Keyword>`HEREDOC`</Keyword><br/>
+<Here Document>    echo "hello"</Here Document><br/>
+<Keyword>HEREDOC</Keyword><br/>
+<Normal Text></Normal Text><br/>
+<Comment># do not highlight HEREDOC markers after the "class" keyword</Comment><br/>
+<Comment># (singleton class definition) (bug: #358273)</Comment><br/>
+<Keyword>class</Keyword><Normal Text> </Normal Text><Operator><<</Operator><Constant>Foo</Constant><Normal Text> </Normal Text><Operator>=</Operator><Normal Text> </Normal Text><Constant>Object</Constant><Message>.new</Message><br/>
+<Normal Text>  </Normal Text><Attribute Definition>attr_accessor</Attribute Definition><Normal Text> </Normal Text><Symbol>:foo</Symbol><br/>
+<Keyword>end</Keyword><br/>
+<Normal Text>singleton_class </Normal Text><Operator>=</Operator><Normal Text> ( </Normal Text><Keyword>class</Keyword><Normal Text> </Normal Text><Operator><<</Operator><Normal Text>foo; </Normal Text><Pseudo variable>self</Pseudo variable><Normal Text>; </Normal Text><Keyword>end</Keyword><Normal Text> )</Normal Text><br/>
+<Normal Text></Normal Text><br/>
+<Comment># highlight regular expressions after ": " (bug: #361875)</Comment><br/>
+<Normal Text>get </Normal Text><Raw String>'files/:slug/:filename'</Raw String><Normal Text>, </Normal Text><Symbol>to: </Symbol><Raw String>'files#download'</Raw String><Normal Text>, </Normal Text><Symbol>slug: </Symbol><Regular Expression>/^[a-z]+$/</Regular Expression><Normal Text>, </Normal Text><Symbol>filename: </Symbol><GDL input>%r|</GDL input><Regular Expression>^[/\s]+$</Regular Expression><GDL input>|</GDL input><br/>
+<Symbol>@@hello!: </Symbol><Regular Expression>/regexp/</Regular Expression><br/>
+<Symbol>[]=: </Symbol><GDL input>%r!</GDL input><Regular Expression>regexp</Regular Expression><GDL input>!</GDL input><br/>
diff --git a/data/syntax/ruby.xml b/data/syntax/ruby.xml
--- a/data/syntax/ruby.xml
+++ b/data/syntax/ruby.xml
@@ -31,7 +31,7 @@
 
 <!-- Hold the "language" opening tag on a single line, as mentioned in "language.dtd". -->
 <language name="Ruby" section="Scripts"
-	  version="9" kateversion="3.3"
+	  version="10" kateversion="3.3"
 	  extensions="*.rb;*.rjs;*.rxml;*.xml.erb;*.js.erb;*.rake;Rakefile;Gemfile;*.gemspec;Vagrantfile"
 	  mimetype="application/x-ruby"
 	  style="ruby" indenter="ruby"
@@ -179,11 +179,11 @@
 			<item>warn</item>
 		</list>
 
-                <list name="mixin-methods">
-                  <item>extend</item>
-                  <item>include</item>
-                  <item>prepend</item>
-                </list>
+		<list name="mixin-methods">
+			<item>extend</item>
+			<item>include</item>
+			<item>prepend</item>
+		</list>
 
 		<contexts>
 			<context name="Normal" attribute="Normal Text" lineEndContext="#stay">
@@ -204,7 +204,7 @@
 				<RegExpr attribute="Keyword" String="\;\s*(while|until)\b(?!.*\bdo\b)" context="#stay" beginRegion="def block"/>
 				<RegExpr attribute="Keyword" String="(if|unless)\b" context="#stay" beginRegion="def block" firstNonSpace="true"/>
 				<RegExpr attribute="Keyword" String="\;\s*(if|unless)\b" context="#stay" beginRegion="def block"/>
-				<WordDetect attribute="Keyword" String="class" context="#stay" beginRegion="def block"/>
+				<WordDetect attribute="Keyword" String="class" context="no_heredoc" beginRegion="def block"/>
 				<WordDetect attribute="Keyword" String="module" context="#stay" beginRegion="def block"/>
 				<WordDetect attribute="Keyword" String="begin" context="#stay" beginRegion="def block"/>
 				<RegExpr attribute="Keyword" String="\bfor\b(?!.*\bdo\b)" context="#stay" beginRegion="def block"/>
@@ -231,7 +231,7 @@
 				<keyword attribute="Pseudo variable" String="pseudo-variables"  context="check_div_1"/>
 				<keyword attribute="Default globals" String="default-globals" context="check_div_2"/>
 				<keyword attribute="Kernel methods" String="kernel-methods" context="check_div_2"/>
-                                <keyword attribute="Module mixin methods" String="mixin-methods" context="check_div_2"/>
+				<keyword attribute="Module mixin methods" String="mixin-methods" context="check_div_2"/>
 
 				<!-- (global) vars starting with $
 						Match them before $_.
@@ -263,8 +263,8 @@
 					push operator '<<' than requiring to put space between the operator
 					and the string.
 				-->
-				<RegExpr attribute="Operator" context="find_indented_heredoc" String="\s*&lt;&lt;-(?=\w+|[&quot;'])" beginRegion="HereDocument" />
-				<RegExpr attribute="Operator" context="find_heredoc" String="\s*&lt;&lt;(?=\w+|[&quot;'])" beginRegion="HereDocument" />
+				<RegExpr attribute="Operator" context="find_indented_heredoc" String="\s*&lt;&lt;[-~](?=\w+|[&quot;'`])" beginRegion="HereDocument" />
+				<RegExpr attribute="Operator" context="find_heredoc" String="\s*&lt;&lt;(?=\w+|[&quot;'`])" beginRegion="HereDocument" />
 
 				<DetectChar attribute="Operator" char="." context="#stay"/>
 				<Detect2Chars attribute="Operator" char="&amp;" char1="&amp;" context="#stay"/>
@@ -280,8 +280,10 @@
 				<RegExpr attribute="Symbol" String=":(@{1,2}|\$)?[a-zA-Z_][a-zA-Z0-9_]*[=?!]?" context="check_div_1"/>
 				<RegExpr attribute="Symbol" String=":\[\]=?" context="check_div_1"/>
 
-				<RegExpr attribute="Symbol" String="(@{1,2}|\$)?[a-zA-Z_][a-zA-Z0-9_]*[=?!]?: " context="check_div_1"/>
-				<RegExpr attribute="Symbol" String="\[\]=?: " context="check_div_1"/>
+				<!-- Do not send to "check_div_1" context!:
+				     after detecting these rules (": ") there can be a regular expression (see bug: #361875) -->
+				<RegExpr attribute="Symbol" String="(@{1,2}|\$)?[a-zA-Z_][a-zA-Z0-9_]*[=?!]?: " context="#stay"/>
+				<RegExpr attribute="Symbol" String="\[\]=?: " context="#stay"/>
 
 				<DetectChar attribute="String" char="&quot;" context="Quoted String"/>
 				<DetectChar attribute="Raw String" char="'" context="Apostrophed String"/>
@@ -436,13 +438,17 @@
 				The contexts below support both normal and indented heredocs
 			 -->
 			<!-- here we markup the heredoc markers -->
-			<context name="find_heredoc" attribute="Normal Text" lineEndContext="#pop" >
+			<context name="find_heredoc" attribute="Normal Text" lineEndContext="#pop" fallthrough="true" fallthroughContext="#pop">
 				<RegExpr attribute="Keyword" context="apostrophed_normal_heredoc" String="'(\w+)'" />
-				<RegExpr attribute="Keyword" context="normal_heredoc" String="&quot;?(\w+)&quot;?" />
+				<RegExpr attribute="Keyword" context="normal_heredoc" String="(\w+)" />
+				<RegExpr attribute="Keyword" context="normal_heredoc" String="&quot;(\w+)&quot;" />
+				<RegExpr attribute="Keyword" context="normal_heredoc" String="`(\w+)`" />
 			</context>
-			<context name="find_indented_heredoc" attribute="Normal Text" lineEndContext="#pop" >
+			<context name="find_indented_heredoc" attribute="Normal Text" lineEndContext="#pop" fallthrough="true" fallthroughContext="#pop">
 				<RegExpr attribute="Keyword" context="apostrophed_indented_heredoc" String="'(\w+)'" />
-				<RegExpr attribute="Keyword" context="indented_heredoc" String="&quot;?(\w+)&quot;?" />
+				<RegExpr attribute="Keyword" context="indented_heredoc" String="(\w+)" />
+				<RegExpr attribute="Keyword" context="indented_heredoc" String="&quot;(\w+)&quot;" />
+				<RegExpr attribute="Keyword" context="indented_heredoc" String="`(\w+)`" />
 			</context>
 			<!-- these are the real heredoc contexts -->
 			<context name="indented_heredoc" attribute="Here Document" lineEndContext="#stay" dynamic="true">
@@ -467,6 +473,16 @@
 				<Detect2Chars attribute="Substitution" char="#" char1="{" context="Subst"/>
 			</context>
 
+			<!-- avoid highlighting heredoc markers, for example, in singleton class definition (see bug: #358273) -->
+			<context name="no_heredoc" attribute="Normal Text" lineEndContext="#stay" fallthrough="true" fallthroughContext="#pop">
+				<DetectSpaces />
+				<Detect2Chars attribute="Operator" char="&lt;" char1="&lt;" context="#pop"/>
+				<!-- comments -->
+				<RegExpr attribute="Comment" String="#\s*BEGIN.*$"  context="#stay" beginRegion="marker" column="0"/>
+				<RegExpr attribute="Comment" String="#\s*END.*$"  context="#stay" endRegion="marker" column="0"/>
+				<DetectChar attribute="Comment" char="#" context="General Comment"/>
+			</context>
+
 			<!-- General delimited input support
 				The contexts below handle the various gdl formats
 			 -->
@@ -892,7 +908,7 @@
 			<itemData name="Constant" defStyleNum="dsDataType"/>
 			<itemData name="Constant Value" defStyleNum="dsDataType" color="#bb1188"/>
 			<itemData name="Kernel methods" defStyleNum="dsNormal" color="#000080" selColor="#ffffff"/> <!-- #CC0E86 -->
-                        <itemData name="Module mixin methods" defStyleNum="dsNormal" color="#000080" selColor="#ffffff"/> <!-- #CC0E86 -->
+			<itemData name="Module mixin methods" defStyleNum="dsNormal" color="#000080" selColor="#ffffff"/> <!-- #CC0E86 -->
 			<itemData name="Member" defStyleNum="dsNormal"/>
 			<itemData name="Instance Variable" defStyleNum="dsOthers"/>
 			<itemData name="Class Variable" defStyleNum="dsOthers"/>
@@ -913,3 +929,5 @@
 		<keywords casesensitive="1" weakDeliminator="!?"/>
 	</general>
 </language>
+
+<!-- kate: replace-tabs off; -->