Some tidying up, name changes and clarifications. I went with "defaultValue"

rather than "missingVariableValue" because the value is used any time a
variable resolves to null, not necessarily just when it is missing. If you
have a context like:

new Object() {
   String foo = null;
}

and reference {{foo}} in your template, foo is not missing, per se, but the
default value will still be used for it.

src/main/java/com/samskivert/mustache/Template.java

@@ -126,10 +126,14 @@ public class Template
         return null;
     }
 
-    protected Object getValueWithDefault (Context ctx, String name, int line)
+    /**
+     * Returns the value for the specified variable, or the configured default value if the
+     * variable resolves to null. See {@link #getValue}.
+     */
+    protected Object getValueOrDefault (Context ctx, String name, int line)
     {
         Object value = getValue(ctx, name, line);
-        return value != null? value : _compiler.missingVariableValue;
+        return (value == null) ? _compiler.defaultValue : value;
     }
 
     protected Object getValueIn (Object data, String name, int line)