diff --git a/Gemfile b/Gemfile
index 39089ade2..671931dc9 100644
--- a/Gemfile
+++ b/Gemfile
@@ -3,7 +3,7 @@ source 'https://rubygems.org'
 ruby '>= 2.7.0', '< 3.3.0'
 
 gem 'rails', '6.1.7'
-gem 'rouge', '~> 3.30.0'
+gem 'rouge', '~> 4.0.0'
 gem 'request_store', '~> 1.5.0'
 gem 'mini_mime', '~> 1.1.0'
 gem "actionpack-xml_parser"
diff --git a/public/help/code_highlighting_languages.html b/public/help/code_highlighting_languages.html
index 51435631f..eda279942 100644
--- a/public/help/code_highlighting_languages.html
+++ b/public/help/code_highlighting_languages.html
@@ -662,6 +662,10 @@
       <td>rescript</td>
       <td>The ReScript programming language (rescript-lang.org)</td>
     </tr>
+    <tr>
+      <td>rml</td>
+      <td>A system agnostic domain-specific language for runtime monitoring and verification (https://rmlatdibris.github.io/)</td>
+    </tr>
     <tr>
       <td>robot_framework</td>
       <td>Robot Framework is a generic open source automation testing framework (robotframework.org) [aliases: robot,robot-framework]</td>
@@ -726,10 +730,6 @@
       <td>sml</td>
       <td>Standard ML [aliases: ml]</td>
     </tr>
-    <tr>
-      <td>solidity</td>
-      <td>Solidity, an Ethereum smart contract programming language</td>
-    </tr>
     <tr>
       <td>sparql</td>
       <td>Semantic Query Language, for RDF data</td>
@@ -792,7 +792,7 @@
     </tr>
     <tr>
       <td>toml</td>
-      <td>the TOML configuration format (https://github.com/mojombo/toml)</td>
+      <td>the TOML configuration format (https://github.com/toml-lang/toml)</td>
     </tr>
     <tr>
       <td>tsx</td>