diff --git a/assets/highlighting-tests/go.go b/assets/highlighting-tests/go.go
new file mode 100644
index 00000000000..3b6bf3e0602
--- /dev/null
+++ b/assets/highlighting-tests/go.go
@@ -0,0 +1,108 @@
+// Comments
+// Single-line comment
+
+/*
+ * Multi-line
+ * comment
+ */
+
+package main
+
+import (
+    "fmt"
+    "time"
+)
+
+const Pi = 3.14
+var enabled = true
+
+// Numbers
+42
+3.14
+.5
+1e10
+1.5e-3
+0xff
+0XFF
+0b1010
+0o77
+1_000_000
+2.5i
+
+// Constants
+true
+false
+nil
+iota
+
+// Strings and runes
+'a'
+'\n'
+"double quotes with escape: \" \n \t \\"
+`raw string
+spans lines`
+
+// Control flow
+func main() {
+    if enabled {
+        fmt.Println("enabled")
+    } else {
+        fmt.Println("disabled")
+    }
+
+    for i := 0; i < 10; i++ {
+        if i == 5 {
+            continue
+        }
+        if i == 8 {
+            break
+        }
+    }
+
+    switch now := time.Now().Weekday(); now {
+    case time.Saturday, time.Sunday:
+        fmt.Println("weekend")
+    default:
+        fmt.Println("weekday")
+    }
+
+    values := []int{1, 2, 3}
+    for _, value := range values {
+        fmt.Println(value)
+    }
+
+    ch := make(chan int, 1)
+    go func() {
+        defer close(ch)
+        ch <- 42
+    }()
+
+    select {
+    case msg := <-ch:
+        fmt.Println(msg)
+    default:
+        fmt.Println("no message")
+    }
+}
+
+type Speaker interface {
+    Speak() string
+}
+
+type Animal struct {
+    Name string
+}
+
+func (a Animal) Speak() string {
+    return fmt.Sprintf("%s speaks", a.Name)
+}
+
+func greet(name string) string {
+    return fmt.Sprintf("hello %s", name)
+}
+
+var _ Speaker = Animal{}
+
+// Function calls
+fmt.Println(greet("world"))
+time.Now()
diff --git a/assets/highlighting-tests/java.java b/assets/highlighting-tests/java.java
new file mode 100644
index 00000000000..9e62f0da8fa
--- /dev/null
+++ b/assets/highlighting-tests/java.java
@@ -0,0 +1,93 @@
+// Comments
+// Single-line comment
+
+/*
+ * Multi-line
+ * comment
+ */
+
+package example;
+
+import java.time.Instant;
+import java.util.List;
+
+@Deprecated
+public class Demo {
+    private static final double PI = 3.14;
+    private boolean enabled = true;
+
+    // Numbers
+    int decimal = 42;
+    double fraction = 3.14;
+    double leadingDot = .5;
+    double scientific = 1.5e-3;
+    int hex = 0xff;
+    int binary = 0b1010;
+    long grouped = 1_000_000L;
+    float floatValue = 2.5f;
+
+    // Constants
+    boolean yes = true;
+    boolean no = false;
+    Object nothing = null;
+
+    // Strings and chars
+    char letter = 'a';
+    char newline = '\n';
+    String message = "double quotes with escape: \" \n \t \\";
+
+    public static void main(String[] args) {
+        Demo demo = new Demo();
+        if (demo.enabled) {
+            System.out.println("enabled");
+        } else {
+            System.out.println("disabled");
+        }
+
+        for (int i = 0; i < 10; i++) {
+            if (i == 5) {
+                continue;
+            }
+            if (i == 8) {
+                break;
+            }
+        }
+
+        while (false) {
+            break;
+        }
+
+        switch (args.length) {
+            case 0:
+                System.out.println("no args");
+                break;
+            default:
+                System.out.println("args");
+        }
+
+        try {
+            demo.run();
+        } catch (IllegalStateException ex) {
+            throw ex;
+        } finally {
+            System.out.println(Instant.now());
+        }
+    }
+
+    public void run() {
+        List<String> names = List.of("Ada", "Grace");
+        for (String name : names) {
+            System.out.println(greet(name));
+        }
+    }
+
+    public String greet(String name) {
+        return "hello " + name;
+    }
+}
+
+record Point(int x, int y) {}
+
+sealed interface Shape permits Circle {}
+
+final class Circle implements Shape {}
diff --git a/assets/highlighting-tests/markdown.md b/assets/highlighting-tests/markdown.md
index 555b182f961..05f7ffa2155 100644
--- a/assets/highlighting-tests/markdown.md
+++ b/assets/highlighting-tests/markdown.md
@@ -66,12 +66,30 @@ Reference: ![Logo][logo-ref]
 echo "Hello, world" | tr a-z A-Z
 ```
 
+```go
+package main
+
+import "fmt"
+
+func main() {
+    fmt.Println("hello")
+}
+```
+
 ```javascript
 export function greet(name) {
   return `hello ${name}`;
 }
 ```
 
+```java
+class Demo {
+  static void main(String[] args) {
+    System.out.println("hello");
+  }
+}
+```
+
 ```json
 {
   "name": "gfm-kitchen-sink",
diff --git a/crates/lsh/definitions/go.lsh b/crates/lsh/definitions/go.lsh
new file mode 100644
index 00000000000..920fc19cea5
--- /dev/null
+++ b/crates/lsh/definitions/go.lsh
@@ -0,0 +1,59 @@
+#[display_name = "Go"]
+#[path = "**/*.go"]
+pub fn go() {
+    until /$/ {
+        yield other;
+
+        if /\/\/.*/ {
+            yield comment;
+        } else if /\/\*/ {
+            loop {
+                yield comment;
+                await input;
+                if /\*\// {
+                    yield comment;
+                    break;
+                }
+            }
+        } else if /'/ {
+            until /$/ {
+                yield string;
+                if /\\./ {}
+                else if /'/ { yield string; break; }
+                await input;
+            }
+        } else if /"/ {
+            until /$/ {
+                yield string;
+                if /\\./ {}
+                else if /"/ { yield string; break; }
+                await input;
+            }
+        } else if /`/ {
+            loop {
+                yield string;
+                if /[^`]*/ {}
+                if /`/ { yield string; break; }
+                await input;
+            }
+        } else if /(?:break|case|continue|default|defer|else|fallthrough|for|goto|if|range|return|select|switch)\>/ {
+            yield keyword.control;
+        } else if /(?:chan|const|func|go|import|interface|map|package|struct|type|var)\>/ {
+            yield keyword.other;
+        } else if /(?:true|false|iota|nil)\>/ {
+            yield constant.language;
+        } else if /(?i:-?(?:0x[\da-fA-F_]+|0b[01_]+|0o[0-7_]+|[\d_]+\.?[\d_]*|\.[\d_]+)(?:p[+-]?[\d_]+|e[+-]?[\d_]+)?i?)/ {
+            if /\w+/ {
+                // Invalid numeric literal
+            } else {
+                yield constant.numeric;
+            }
+        } else if /(\w+)\s*\(/ {
+            yield $1 as method;
+        } else if /\w+/ {
+            // Gobble word chars to align the next iteration on a word boundary.
+        }
+
+        yield other;
+    }
+}
diff --git a/crates/lsh/definitions/java.lsh b/crates/lsh/definitions/java.lsh
new file mode 100644
index 00000000000..e203eecfd2a
--- /dev/null
+++ b/crates/lsh/definitions/java.lsh
@@ -0,0 +1,56 @@
+#[display_name = "Java"]
+#[path = "**/*.java"]
+pub fn java() {
+    until /$/ {
+        yield other;
+
+        if /\/\/.*/ {
+            yield comment;
+        } else if /\/\*/ {
+            loop {
+                yield comment;
+                await input;
+                if /\*\// {
+                    yield comment;
+                    break;
+                }
+            }
+        } else if /'/ {
+            until /$/ {
+                yield string;
+                if /\\./ {}
+                else if /'/ { yield string; break; }
+                await input;
+            }
+        } else if /"/ {
+            until /$/ {
+                yield string;
+                if /\\./ {}
+                else if /"/ { yield string; break; }
+                await input;
+            }
+        } else if /(?:break|case|catch|continue|default|do|else|finally|for|if|return|switch|throw|throws|try|while)\>/ {
+            yield keyword.control;
+        } else if /(?:abstract|assert|class|enum|extends|final|implements|import|instanceof|interface|module|native|new|package|private|protected|public|record|sealed|static|strictfp|super|synchronized|this|transient|volatile)\>/ {
+            yield keyword.other;
+        } else if /(?:boolean|byte|char|double|float|int|long|short|void|var)\>/ {
+            yield keyword.other;
+        } else if /(?:true|false|null)\>/ {
+            yield constant.language;
+        } else if /@\w+/ {
+            yield markup.link;
+        } else if /(?i:-?(?:0x[\da-fA-F_]+|0b[01_]+|[\d_]+\.?[\d_]*|\.[\d_]+)(?:p[+-]?[\d_]+|e[+-]?[\d_]+)?[dfl]?)/ {
+            if /\w+/ {
+                // Invalid numeric literal
+            } else {
+                yield constant.numeric;
+            }
+        } else if /(\w+)\s*\(/ {
+            yield $1 as method;
+        } else if /\w+/ {
+            // Gobble word chars to align the next iteration on a word boundary.
+        }
+
+        yield other;
+    }
+}
diff --git a/crates/lsh/definitions/markdown.lsh b/crates/lsh/definitions/markdown.lsh
index 77a005fe925..5bd91395dc9 100644
--- a/crates/lsh/definitions/markdown.lsh
+++ b/crates/lsh/definitions/markdown.lsh
@@ -28,6 +28,16 @@ pub fn markdown() {
                     if /.*/ {}
                 }
             }
+        } else if /(?i:go|golang)/ {
+            loop {
+                await input;
+                if /\s*```/ {
+                    return;
+                } else {
+                    go();
+                    if /.*/ {}
+                }
+            }
         } else if /(?i:diff)/ {
             loop {
                 await input;
@@ -50,6 +60,16 @@ pub fn markdown() {
                     if /.*/ {}
                 }
             }
+        } else if /(?i:java)/ {
+            loop {
+                await input;
+                if /\s*```/ {
+                    return;
+                } else {
+                    java();
+                    if /.*/ {}
+                }
+            }
         } else if /(?i:json)/ {
             loop {
                 await input;