diff --git a/doc/guide/author/topics.xml b/doc/guide/author/topics.xml
index 59dfe420b..58f2856ca 100644
--- a/doc/guide/author/topics.xml
+++ b/doc/guide/author/topics.xml
@@ -4067,6 +4067,12 @@
                         <cell></cell>
                         <cell>AC + IO</cell>
                     </row>
+                    <row>
+                        <cell>GDScript</cell>
+                        <cell><c>gdscript</c></cell>
+                        <cell></cell>
+                        <cell>AC</cell>
+                    </row>
                     <row>
                         <cell>Java</cell>
                         <cell><c>java</c></cell>
diff --git a/doc/guide/publisher/publication-file.xml b/doc/guide/publisher/publication-file.xml
index 7c20f017d..5cf6cea6e 100644
--- a/doc/guide/publisher/publication-file.xml
+++ b/doc/guide/publisher/publication-file.xml
@@ -585,6 +585,7 @@
                         <li><c>cpp</c> (C++, Runestone server only)</li>
                         <li><c>java</c> (Java, Runestone server only)</li>
                         <li><c>kotlin</c> (Kotlin, Runestone server only)</li>
+                        <li><c>gdscript</c> (GDScript, Runestone server only)</li>
                         <li><c>python3</c> (Python 3, Runestone server only)</li>
                         <li><c>octave</c> (Octave, Runestone server only)</li>
                         <li><c>none</c></li>
diff --git a/doc/guide/publisher/runestone.xml b/doc/guide/publisher/runestone.xml
index f68b2edd6..4c03b53d5 100644
--- a/doc/guide/publisher/runestone.xml
+++ b/doc/guide/publisher/runestone.xml
@@ -29,7 +29,7 @@
 
             <li>As much as possible, non-interactive versions of these problems will render in less-capable formats, like <init>PDF</init>, <init>EPUB</init>, and braille.</li>
 
-            <li>A <tag>program</tag> element with the attribute <attr>interactive</attr> set to <c>activecode</c> (even outside of a an exercise) will be realized as a Runestone ActiveCode interactive program, where programs can be edited, compiled, and run.  In some cases a CodeLens interactive trace utility is also available.  The <attr>language</attr> must be set.  Supported values for the language when hosted at Runestone are: <c>python</c>, <c>python3</c>, <c>c</c>, <c>cpp</c> (C++), <c>javascript</c>, <c>java</c>, <c>kotlin</c>, <c>octave</c> (Matlab), <c>sql</c>, and <c>html</c>.  When hosted on your own server, <c>python</c>, <c>javascript</c>, <c>sql</c>, and <c>html</c>, are supported with in-browser routines.  So you do not need to configure <em>anything</em> server-side for this capability.  See subsections of <xref ref="interactive-program-activecode"/> for details.</li>
+            <li>A <tag>program</tag> element with the attribute <attr>interactive</attr> set to <c>activecode</c> (even outside of a an exercise) will be realized as a Runestone ActiveCode interactive program, where programs can be edited, compiled, and run.  In some cases a CodeLens interactive trace utility is also available.  The <attr>language</attr> must be set.  Supported values for the language when hosted at Runestone are: <c>python</c>, <c>python3</c>, <c>c</c>, <c>cpp</c> (C++), <c>gdscript</c>, <c>javascript</c>, <c>java</c>, <c>kotlin</c>,  <c>octave</c> (Matlab), <c>sql</c>, and <c>html</c>.  When hosted on your own server, <c>python</c>, <c>javascript</c>, <c>sql</c>, and <c>html</c>, are supported with in-browser routines.  So you do not need to configure <em>anything</em> server-side for this capability.  See subsections of <xref ref="interactive-program-activecode"/> for details.</li>
 
             <li>Similarly, a <tag>program</tag> element with the attribute <attr>interactive</attr> set to <c>codelens</c> (even outside of a an exercise) will be realized as a Runestone CodeLens interactive program.  This allows a reader to step through the program, much like in a debugger, but with more informative displays of the intermediate state of the program (and nothing like breakpoints or changing variable's values).  This ability varies by language, and by hosting location.    See subsections of <xref ref="interactive-program-codelens"/> for details.</li>
 
diff --git a/examples/sample-book/rune.xml b/examples/sample-book/rune.xml
index e78e94a6b..083943e79 100644
--- a/examples/sample-book/rune.xml
+++ b/examples/sample-book/rune.xml
@@ -88,6 +88,7 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
             </program>
         </listing>
 
+
         <p>Otherwise they are rendered as text with syntax coloring. Either way, if a <attr>language</attr> is not specified, <c>docinfo/programs/@language</c> will be checked to determine what language to assume the code is written in.
         </p>
 
@@ -116,6 +117,21 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
             </program>
         </listing>
 
+        <p>A GDScript program will only be interactive if hosted on a Runestone server.</p>
+        <!-- Note: It may be possible to embed a mini ActiveCode Style IDE for GDScript  -->
+        <!--       on the web page, but it's not implemented yet. -->
+
+        <listing xml:id="program-activecode-gdscript">
+            <title>An interactive GDScript program, using <pubtitle>Runestone</pubtitle></title>
+            <program xml:id="gdscript-hello-world" interactive='activecode' language="gdscript" label="gd-hello-world">
+                <code>
+                    var language : String = "GDScript" 
+                    print("Hello, " + language)
+
+                </code>
+            </program>
+        </listing>
+
         <p>A Java program will only be interactive if hosted on a Runestone server.</p>
 
         <listing xml:id="program-activecode-java">
diff --git a/schema/publication-schema.xml b/schema/publication-schema.xml
index ee81b6440..0db990161 100644
--- a/schema/publication-schema.xml
+++ b/schema/publication-schema.xml
@@ -388,7 +388,7 @@
             Calculator =
                 element calculator {
                     attribute model { "geogebra-classic" | "geogebra-graphing" | "geogebra-geometry" | "geogebra-3d" | "none "}?,
-                    attribute activecode { "python" | "javascript" | "html" | "sql" | "c" | "cpp" | "java" | "kotlin" | "python3" | "octave" | "none"}?
+                    attribute activecode { "python" | "javascript" | "html" | "sql" | "c" | "cpp" | "gdscript" | "java" | "kotlin" | "python3" | "octave" | "none"}?
                 }
 
             Crossreferences =
diff --git a/xsl/pretext-common.xsl b/xsl/pretext-common.xsl
index e63a78d2a..f1c468530 100644
--- a/xsl/pretext-common.xsl
+++ b/xsl/pretext-common.xsl
@@ -8026,6 +8026,7 @@ Book (with parts), "section" at level 3
     <language ptx="basic"       active=""            listings="Basic"            prism="basic"/>
     <language ptx="c"           active="c"           listings="C"                prism="c"/>
     <language ptx="cpp"         active="cpp"         listings="C++"              prism="cpp"/>
+    <language ptx="gdscript"    active="gdscript"    listings="Python"           prism="gdscript"/>
     <language ptx="go"          active=""            listings="C"                prism="go"/>
     <language ptx="java"        active="java"        listings="Java"             prism="java"/>
     <language ptx="javascript"  active="javascript"  listings=""                 prism="javascript"/>
diff --git a/xsl/pretext-html.xsl b/xsl/pretext-html.xsl
index 1e9b4fd94..9800687bc 100644
--- a/xsl/pretext-html.xsl
+++ b/xsl/pretext-html.xsl
@@ -13918,6 +13918,46 @@ TODO:
     <xsl:if test="$b-has-program and not($b-debug-react)">
         <script src="https://cdnjs.cloudflare.com/ajax/libs/prism/1.26.0/components/prism-core.min.js"></script>
         <script src="https://cdnjs.cloudflare.com/ajax/libs/prism/1.26.0/plugins/autoloader/prism-autoloader.min.js"></script>
+
+        <!-- INJECT GDSCRIPT 2 GRAMMAR VIA PRISM HOOKS -->
+        <script type="text/javascript">
+            <![CDATA[
+            (function() {
+                if (!window.Prism) return;
+                
+                // Define grammar using safe string-based RegExp constructors
+                var gdscript2Grammar = {
+                    'comment': new RegExp('#.*'),
+                    'string': {
+                        pattern: new RegExp('(?:r|f|b)?(?:"(?:\\\\.|[^"\\\\])*"|\'(?:\\\\.|[^\'\\\\])*\')', 'i'),
+                        greedy: true
+                    },
+                    'annotation': {
+                        pattern: new RegExp('@\\w+'),
+                        alias: 'builtin'
+                    },
+                    'keyword': new RegExp('\\b(?:as|assert|await|break|breakpoint|class|class_name|const|continue|enum|export|extends|for|func|if|elif|else|in|is|match|onready|pass|preload|return|self|setget|signal|static|super|tool|var|void|while|yield)\\b'),
+                    'function': new RegExp('\\b[a-z_]\\w*(?=\\s*\\()', 'i'),
+                    'number': new RegExp('\\b(?:0b+|0x[\\da-fA-F]+|\\d+(?:\\.\\d+)?(?:e[+-]?\\d+)?)\\b'),
+                    'boolean': new RegExp('\\b(?:true|false)\\b'),
+                    'operator': new RegExp('->|:=|&&|\\|\\||[-+*/%&|^!=<>]=?|~'),
+                    'punctuation': new RegExp('[{}[\\];(),.:]')
+                };
+
+                // Hook into Prism's token initialization pipeline
+                Prism.hooks.add('before-tokenize', function(env) {
+                    if (env.language === 'gdscript') {
+                        Prism.languages.gdscript = gdscript2Grammar;
+                    }
+                });
+                
+                // Pre-register it globally
+                Prism.languages.gdscript = gdscript2Grammar;
+            })();
+            ]]>
+        </script>
+
+
         <script src="https://cdnjs.cloudflare.com/ajax/libs/prism/1.26.0/plugins/line-numbers/prism-line-numbers.min.js" integrity="sha512-dubtf8xMHSQlExGRQ5R7toxHLgSDZ0K7AunqPWHXmJQ8XyVIG19S1T95gBxlAeGOK02P4Da2RTnQz0Za0H0ebQ==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>
         <script src="https://cdnjs.cloudflare.com/ajax/libs/prism/1.26.0/plugins/line-highlight/prism-line-highlight.min.js" integrity="sha512-93uCmm0q+qO5Lb1huDqr7tywS8A2TFA+1/WHvyiWaK6/pvsFl6USnILagntBx8JnVbQH5s3n0vQZY6xNthNfKA==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>
         <xsl:if test="$b-html-theme-legacy or $b-reveal-build" >
diff --git a/xsl/pretext-runestone.xsl b/xsl/pretext-runestone.xsl
index 8b392bc5d..5553bb84c 100644
--- a/xsl/pretext-runestone.xsl
+++ b/xsl/pretext-runestone.xsl
@@ -2717,6 +2717,7 @@ along with PreTeXt.  If not, see <http://www.gnu.org/licenses/>.
         <xsl:when test="$language = 'sql'">         <xsl:text>browser</xsl:text></xsl:when>
         <xsl:when test="$language = 'c'">           <xsl:text>jobeserver</xsl:text></xsl:when>
         <xsl:when test="$language = 'cpp'">         <xsl:text>jobeserver</xsl:text></xsl:when>
+        <xsl:when test="$language = 'gdscript'">    <xsl:text>jobeserver</xsl:text></xsl:when>
         <xsl:when test="$language = 'java'">        <xsl:text>jobeserver</xsl:text></xsl:when>
         <xsl:when test="$language = 'kotlin'">      <xsl:text>jobeserver</xsl:text></xsl:when>
         <xsl:when test="$language = 'python2'">     <xsl:text>jobeserver</xsl:text></xsl:when>
diff --git a/xsl/publisher-variables.xsl b/xsl/publisher-variables.xsl
index b3e2541d4..8698f4a41 100644
--- a/xsl/publisher-variables.xsl
+++ b/xsl/publisher-variables.xsl
@@ -1912,6 +1912,7 @@ along with PreTeXt.  If not, see <http://www.gnu.org/licenses/>.
         <!-- languages only available on a Runestone server -->
         <xsl:when test="($entered-lang = 'c') or
                         ($entered-lang = 'cpp') or
+                        ($entered-lang = 'gdscript') or
                         ($entered-lang = 'java') or
                         ($entered-lang = 'kotlin') or
                         ($entered-lang = 'python3') or