Everywhere: Behaviour => Behavior

Userland/Libraries/LibC/scanf.cpp

@@ -547,7 +547,7 @@ extern "C" int vsscanf(const char* input, const char* format, va_list ap)
         case ConversionSpecifier::Invalid:
         case ConversionSpecifier::Unspecified:
         default:
-            // "undefined behaviour", let's be nice and crash.
+            // "undefined behavior", let's be nice and crash.
             dbgln("Invalid conversion specifier {} in scanf!", (int)conversion_specifier);
             VERIFY_NOT_REACHED();
         case ConversionSpecifier::Decimal:

Userland/Libraries/LibCrypto/BigInt/Algorithms/BitwiseOperations.cpp

@@ -241,7 +241,7 @@ ALWAYS_INLINE UnsignedBigInteger::Word UnsignedBigIntegerAlgorithms::shift_left_
     VERIFY(num_bits <= UnsignedBigInteger::BITS_IN_WORD);
     u32 result = 0;
 
-    // we need to check for "num_bits != 0" since shifting right by 32 is apparently undefined behaviour!
+    // we need to check for "num_bits != 0" since shifting right by 32 is apparently undefined behavior!
     if (result_word_index > 0 && num_bits != 0) {
         result += number.m_words[result_word_index - 1] >> (UnsignedBigInteger::BITS_IN_WORD - num_bits);
     }

Userland/Libraries/LibGL/Tex/Sampler2D.cpp

@@ -35,7 +35,7 @@ static constexpr float wrap(float value, GLint mode)
     case GL_REPEAT:
         return wrap_repeat(value);
 
-    // FIXME: These clamp modes actually have slightly different behaviour
+    // FIXME: These clamp modes actually have slightly different behavior
     case GL_CLAMP:
     case GL_CLAMP_TO_BORDER:
     case GL_CLAMP_TO_EDGE:

Userland/Libraries/LibGUI/VimEditingEngine.cpp

@@ -1353,7 +1353,7 @@ void VimEditingEngine::put_after()
         m_editor->set_cursor({ m_editor->cursor().line(), m_editor->current_line().first_non_whitespace_column() });
     } else {
         // FIXME: If attempting to put on the last column a line,
-        // the buffer will bne placed on the next line due to the move_one_left/right behaviour.
+        // the buffer will bne placed on the next line due to the move_one_left/right behavior.
         move_one_right();
         StringBuilder sb = StringBuilder(m_yank_buffer.length() * amount);
         for (auto i = 0; i < amount; i++) {

Userland/Libraries/LibJS/Runtime/Array.cpp

@@ -104,7 +104,7 @@ bool Array::set_length(PropertyDescriptor const& property_descriptor)
     // 15. Let succeeded be ! OrdinaryDefineOwnProperty(A, "length", newLenDesc).
     // 16. If succeeded is false, return false.
     // NOTE: Because the length property does not actually exist calling OrdinaryDefineOwnProperty
-    // will result in unintended behaviour, so instead we only implement here the small subset of
+    // will result in unintended behavior, so instead we only implement here the small subset of
     // checks performed inside of it that would have mattered to us:
 
     // 10.1.6.3 ValidateAndApplyPropertyDescriptor ( O, P, extensible, Desc, current ), https://tc39.es/ecma262/#sec-validateandapplypropertydescriptor

Userland/Libraries/LibJS/Runtime/IteratorOperations.cpp

@@ -115,7 +115,7 @@ void iterator_close(Object& iterator)
     auto& vm = iterator.vm();
     auto& global_object = iterator.global_object();
 
-    // Emulates `completion` behaviour
+    // Emulates `completion` behavior
     auto* completion_exception = vm.exception();
     vm.clear_exception();
     auto unwind_until = vm.unwind_until();

Userland/Libraries/LibJS/Runtime/StringPrototype.cpp

@@ -252,7 +252,7 @@ JS_DEFINE_NATIVE_FUNCTION(StringPrototype::repeat)
     if (n == 0)
         return js_string(vm, String::empty());
 
-    // NOTE: This is an optimization, it is not required by the specification but it produces equivalent behaviour
+    // NOTE: This is an optimization, it is not required by the specification but it produces equivalent behavior
     if (string->is_empty())
         return js_string(vm, String::empty());
 

Userland/Libraries/LibJS/Runtime/Temporal/PlainDate.cpp

@@ -173,7 +173,7 @@ Optional<ISODate> regulate_iso_date(GlobalObject& global_object, double year, do
     // 3. If overflow is "reject", then
     if (overflow == "reject"sv) {
         // IMPLEMENTATION DEFINED: This is an optimization that allows us to treat these doubles as normal integers from this point onwards.
-        // This does not change the exposed behaviour as the call to IsValidISODate will immediately check that these values are valid ISO
+        // This does not change the exposed behavior as the call to IsValidISODate will immediately check that these values are valid ISO
         // values (for years: -273975 - 273975, for months: 1 - 12, for days: 1 - 31) all of which are subsets of this check.
         if (!AK::is_within_range<i32>(year) || !AK::is_within_range<u8>(month) || !AK::is_within_range<u8>(day)) {
             vm.throw_exception<RangeError>(global_object, ErrorType::TemporalInvalidPlainDate);
@@ -193,7 +193,7 @@ Optional<ISODate> regulate_iso_date(GlobalObject& global_object, double year, do
     // 4. If overflow is "constrain", then
     else if (overflow == "constrain"sv) {
         // IMPLEMENTATION DEFINED: This is an optimization that allows us to treat this double as normal integer from this point onwards. This
-        // does not change the exposed behaviour as the parent's call to CreateTemporalDate will immediately check that this value is a valid
+        // does not change the exposed behavior as the parent's call to CreateTemporalDate will immediately check that this value is a valid
         // ISO value for years: -273975 - 273975, which is a subset of this check.
         if (!AK::is_within_range<i32>(year)) {
             vm.throw_exception<RangeError>(global_object, ErrorType::TemporalInvalidPlainDate);

Userland/Libraries/LibJS/Runtime/Temporal/PlainDateConstructor.cpp

@@ -73,7 +73,7 @@ Value PlainDateConstructor::construct(FunctionObject& new_target)
         return {};
 
     // IMPLEMENTATION DEFINED: This is an optimization that allows us to treat these doubles as normal integers from this point onwards.
-    // This does not change the exposed behaviour as the call to CreateTemporalDate will immediately check that these values are valid
+    // This does not change the exposed behavior as the call to CreateTemporalDate will immediately check that these values are valid
     // ISO values (for years: -273975 - 273975, for months: 1 - 12, for days: 1 - 31) all of which are subsets of this check.
     if (!AK::is_within_range<i32>(y) || !AK::is_within_range<u8>(m) || !AK::is_within_range<u8>(d)) {
         vm.throw_exception<RangeError>(global_object, ErrorType::TemporalInvalidPlainDate);

Userland/Libraries/LibJS/Runtime/Temporal/PlainDateTimeConstructor.cpp

@@ -103,7 +103,7 @@ Value PlainDateTimeConstructor::construct(FunctionObject& new_target)
         return {};
 
     // IMPLEMENTATION DEFINED: This is an optimization that allows us to treat these doubles as normal integers from this point onwards.
-    // This does not change the exposed behaviour as the call to CreateTemporalDateTime will immediately check that these values are valid
+    // This does not change the exposed behavior as the call to CreateTemporalDateTime will immediately check that these values are valid
     // ISO values (for years: -273975 - 273975, for months: 1 - 12, for days: 1 - 31, for hours: 0 - 23, for minutes and seconds: 0 - 59,
     // milliseconds, microseconds, and nanoseconds: 0 - 999) all of which are subsets of this check.
     if (!AK::is_within_range<i32>(iso_year) || !AK::is_within_range<u8>(iso_month) || !AK::is_within_range<u8>(iso_day) || !AK::is_within_range<u8>(hour) || !AK::is_within_range<u8>(minute) || !AK::is_within_range<u8>(second) || !AK::is_within_range<u16>(millisecond) || !AK::is_within_range<u16>(microsecond) || !AK::is_within_range<u16>(nanosecond)) {

Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDayConstructor.cpp

@@ -78,7 +78,7 @@ Value PlainMonthDayConstructor::construct(FunctionObject& new_target)
         return {};
 
     // IMPLEMENTATION DEFINED: This is an optimization that allows us to treat these doubles as normal integers from this point onwards.
-    // This does not change the exposed behaviour as the call to CreateTemporalMonthDay will immediately check that these values are valid
+    // This does not change the exposed behavior as the call to CreateTemporalMonthDay will immediately check that these values are valid
     // ISO values (for years: -273975 - 273975, for months: 1 - 12, for days: 1 - 31) all of which are subsets of this check.
     if (!AK::is_within_range<i32>(ref) || !AK::is_within_range<u8>(m) || !AK::is_within_range<u8>(d)) {
         vm.throw_exception<RangeError>(global_object, ErrorType::TemporalInvalidPlainYearMonth);

Userland/Libraries/LibJS/Runtime/Temporal/PlainTimeConstructor.cpp

@@ -81,7 +81,7 @@ Value PlainTimeConstructor::construct(FunctionObject& new_target)
         return {};
 
     // IMPLEMENTATION DEFINED: This is an optimization that allows us to treat these doubles as normal integers from this point onwards.
-    // This does not change the exposed behaviour as the call to CreateTemporalTime will immediately check that these values are valid
+    // This does not change the exposed behavior as the call to CreateTemporalTime will immediately check that these values are valid
     // ISO values (for hours: 0 - 23, for minutes and seconds: 0 - 59, milliseconds, microseconds, and nanoseconds: 0 - 999) all of which
     // are subsets of this check.
     if (!AK::is_within_range<u8>(hour) || !AK::is_within_range<u8>(minute) || !AK::is_within_range<u8>(second) || !AK::is_within_range<u16>(millisecond) || !AK::is_within_range<u16>(microsecond) || !AK::is_within_range<u16>(nanosecond)) {

Userland/Libraries/LibJS/Runtime/Temporal/PlainYearMonth.cpp

@@ -44,7 +44,7 @@ Optional<ISOYearMonth> regulate_iso_year_month(GlobalObject& global_object, doub
     // 3. If overflow is "constrain", then
     if (overflow == "constrain"sv) {
         // IMPLEMENTATION DEFINED: This is an optimization that allows us to treat `year` (a double) as normal integer from this point onwards.
-        // This does not change the exposed behaviour as the subsequent call to CreateTemporalYearMonth will check that its value is a valid ISO
+        // This does not change the exposed behavior as the subsequent call to CreateTemporalYearMonth will check that its value is a valid ISO
         // values (for years: -273975 - 273975) which is a subset of this check.
         // If RegulateISOYearMonth is ever used outside ISOYearMonthFromFields, this may need to be changed.
         if (!AK::is_within_range<i32>(year)) {
@@ -59,7 +59,7 @@ Optional<ISOYearMonth> regulate_iso_year_month(GlobalObject& global_object, doub
     // 4. If overflow is "reject", then
     if (overflow == "reject"sv) {
         // IMPLEMENTATION DEFINED: This is an optimization that allows us to treat these doubles as normal integers from this point onwards.
-        // This does not change the exposed behaviour as the call to IsValidISOMonth and subsequent call to CreateTemporalDateTime will check
+        // This does not change the exposed behavior as the call to IsValidISOMonth and subsequent call to CreateTemporalDateTime will check
         // that these values are valid ISO values (for years: -273975 - 273975, for months: 1 - 12) all of which are subsets of this check.
         if (!AK::is_within_range<i32>(year) || !AK::is_within_range<u8>(month)) {
             vm.throw_exception<RangeError>(global_object, ErrorType::TemporalInvalidPlainYearMonth);

Userland/Libraries/LibJS/Runtime/Temporal/PlainYearMonthConstructor.cpp

@@ -78,7 +78,7 @@ Value PlainYearMonthConstructor::construct(FunctionObject& new_target)
         return {};
 
     // IMPLEMENTATION DEFINED: This is an optimization that allows us to treat these doubles as normal integers from this point onwards.
-    // This does not change the exposed behaviour as the call to CreateTemporalYearMonth will immediately check that these values are valid
+    // This does not change the exposed behavior as the call to CreateTemporalYearMonth will immediately check that these values are valid
     // ISO values (for years: -273975 - 273975, for months: 1 - 12, for days: 1 - 31) all of which are subsets of this check.
     if (!AK::is_within_range<i32>(y) || !AK::is_within_range<u8>(m) || !AK::is_within_range<u8>(ref)) {
         vm.throw_exception<RangeError>(global_object, ErrorType::TemporalInvalidPlainYearMonth);

Userland/Libraries/LibJS/Tests/builtins/TypedArray/TypedArray.prototype.copyWithin.js

@@ -22,7 +22,7 @@ test("length is 2", () => {
     });
 });
 
-describe("normal behaviour", () => {
+describe("normal behavior", () => {
     test("Noop", () => {
         TYPED_ARRAYS.forEach(T => {
             const array = new T([1, 2]);
@@ -37,7 +37,7 @@ describe("normal behaviour", () => {
         });
     });
 
-    test("basic behaviour", () => {
+    test("basic behavior", () => {
         TYPED_ARRAYS.forEach(T => {
             const array = new T([1, 2, 3]);
             expect(array.copyWithin(1, 2)).toEqual(array);

Userland/Libraries/LibJS/Tests/builtins/TypedArray/TypedArray.prototype.filter.js

@@ -112,7 +112,7 @@ describe("errors", () => {
     });
 });
 
-describe("normal behaviour", () => {
+describe("normal behavior", () => {
     test("never calls callback with empty array", () => {
         TYPED_ARRAYS.forEach(T => {
             let callbackCalled = 0;

Userland/Libraries/LibJS/Tests/builtins/TypedArray/TypedArray.prototype.find.js

@@ -44,7 +44,7 @@ describe("errors", () => {
     BIGINT_TYPED_ARRAYS.forEach(T => errorTests(T));
 });
 
-describe("normal behaviour", () => {
+describe("normal behavior", () => {
     test("basic functionality", () => {
         TYPED_ARRAYS.forEach(T => {
             const typedArray = new T([1, 2, 3]);

Userland/Libraries/LibJS/Tests/builtins/TypedArray/TypedArray.prototype.findIndex.js

@@ -44,7 +44,7 @@ describe("errors", () => {
     BIGINT_TYPED_ARRAYS.forEach(T => errorTests(T));
 });
 
-describe("normal behaviour", () => {
+describe("normal behavior", () => {
     test("basic functionality", () => {
         TYPED_ARRAYS.forEach(T => {
             const typedArray = new T([1, 2, 3]);

Userland/Libraries/LibJS/Tests/builtins/TypedArray/TypedArray.prototype.findLast.js

@@ -44,7 +44,7 @@ describe("errors", () => {
     BIGINT_TYPED_ARRAYS.forEach(T => errorTests(T));
 });
 
-describe("normal behaviour", () => {
+describe("normal behavior", () => {
     test("basic functionality", () => {
         TYPED_ARRAYS.forEach(T => {
             const typedArray = new T([1, 2, 3]);

Userland/Libraries/LibJS/Tests/builtins/TypedArray/TypedArray.prototype.findLastIndex.js

@@ -44,7 +44,7 @@ describe("errors", () => {
     BIGINT_TYPED_ARRAYS.forEach(T => errorTests(T));
 });
 
-describe("normal behaviour", () => {
+describe("normal behavior", () => {
     test("basic functionality", () => {
         TYPED_ARRAYS.forEach(T => {
             const typedArray = new T([1, 2, 3]);

Userland/Libraries/LibJS/Tests/builtins/TypedArray/TypedArray.prototype.forEach.js

@@ -44,7 +44,7 @@ describe("errors", () => {
     BIGINT_TYPED_ARRAYS.forEach(T => errorTests(T));
 });
 
-describe("normal behaviour", () => {
+describe("normal behavior", () => {
     test("never calls callback with empty array", () => {
         function emptyTest(T) {
             var callbackCalled = 0;

Userland/Libraries/LibJS/Tests/builtins/TypedArray/TypedArray.prototype.map.js

@@ -144,7 +144,7 @@ describe("errors", () => {
     });
 });
 
-describe("normal behaviour", () => {
+describe("normal behavior", () => {
     test("never calls callback with empty array", () => {
         TYPED_ARRAYS.forEach(T => {
             let callbackCalled = 0;

Userland/Libraries/LibLine/Editor.cpp

@@ -41,11 +41,11 @@ Configuration Configuration::from_config(const StringView& libname)
     Configuration configuration;
     auto config_file = Core::ConfigFile::open_for_lib(libname);
 
-    // Read behaviour options.
-    auto refresh = config_file->read_entry("behaviour", "refresh", "lazy");
-    auto operation = config_file->read_entry("behaviour", "operation_mode");
-    auto bracketed_paste = config_file->read_bool_entry("behaviour", "bracketed_paste", true);
-    auto default_text_editor = config_file->read_entry("behaviour", "default_text_editor");
+    // Read behavior options.
+    auto refresh = config_file->read_entry("behavior", "refresh", "lazy");
+    auto operation = config_file->read_entry("behavior", "operation_mode");
+    auto bracketed_paste = config_file->read_bool_entry("behavior", "bracketed_paste", true);
+    auto default_text_editor = config_file->read_entry("behavior", "default_text_editor");
 
     Configuration::Flags flags { Configuration::Flags::None };
     if (bracketed_paste)
@@ -184,7 +184,7 @@ void Editor::set_default_keybinds()
 Editor::Editor(Configuration configuration)
     : m_configuration(move(configuration))
 {
-    m_always_refresh = m_configuration.refresh_behaviour == Configuration::RefreshBehaviour::Eager;
+    m_always_refresh = m_configuration.refresh_behavior == Configuration::RefreshBehavior::Eager;
     m_pending_chars = {};
     get_terminal_size();
     m_suggestion_display = make<XtermSuggestionDisplay>(m_num_lines, m_num_columns);
@@ -1024,8 +1024,8 @@ void Editor::handle_read_event()
         ArmedScopeGuard suggestion_cleanup { [this] { cleanup_suggestions(); } };
 
         // Normally ^D. `stty eof \^n` can change it to ^N (or something else), but Serenity doesn't have `stty` yet.
-        // Process this here since the keybinds might override its behaviour.
-        // This only applies when the buffer is empty. at any other time, the behaviour should be configurable.
+        // Process this here since the keybinds might override its behavior.
+        // This only applies when the buffer is empty. at any other time, the behavior should be configurable.
         if (code_point == m_termios.c_cc[VEOF] && m_buffer.size() == 0) {
             finish_edit();
             continue;

Userland/Libraries/LibLine/Editor.h

@@ -45,7 +45,7 @@ struct KeyBinding {
 };
 
 struct Configuration {
-    enum RefreshBehaviour {
+    enum RefreshBehavior {
         Lazy,
         Eager,
     };
@@ -80,7 +80,7 @@ struct Configuration {
         set(arg);
     }
 
-    void set(RefreshBehaviour refresh) { refresh_behaviour = refresh; }
+    void set(RefreshBehavior refresh) { refresh_behavior = refresh; }
     void set(OperationMode mode) { operation_mode = mode; }
     void set(SignalHandler mode) { m_signal_mode = mode; }
     void set(const KeyBinding& binding) { keybindings.append(binding); }
@@ -92,7 +92,7 @@ struct Configuration {
 
     static Configuration from_config(const StringView& libname = "line");
 
-    RefreshBehaviour refresh_behaviour { RefreshBehaviour::Lazy };
+    RefreshBehavior refresh_behavior { RefreshBehavior::Lazy };
     SignalHandler m_signal_mode { SignalHandler::WithSignalHandlers };
     OperationMode operation_mode { OperationMode::Unset };
     Vector<KeyBinding> keybindings;

Userland/Libraries/LibRegex/RegexOptions.h

@@ -34,7 +34,7 @@ enum class AllFlags {
     Multiline = __Regex_Multiline,                               // Handle newline characters. Match each line, one by one.
     SkipTrimEmptyMatches = __Regex_SkipTrimEmptyMatches,         // Do not remove empty capture group results.
     Internal_Stateful = __Regex_Internal_Stateful,               // Make global matches match one result at a time, and further match() calls on the same instance continue where the previous one left off.
-    Internal_BrowserExtended = __Regex_Internal_BrowserExtended, // Only for ECMA262, Enable the behaviours defined in section B.1.4. of the ECMA262 spec.
+    Internal_BrowserExtended = __Regex_Internal_BrowserExtended, // Only for ECMA262, Enable the behaviors defined in section B.1.4. of the ECMA262 spec.
     Last = Internal_BrowserExtended,
 };
 

Userland/Libraries/LibRegex/RegexParser.h

@@ -260,7 +260,7 @@ private:
     // Most patterns should have no need to ever populate this field.
     Optional<size_t> m_total_number_of_capturing_parenthesis;
 
-    // Keep the Annex B. behaviour behind a flag, the users can enable it by passing the `ECMAScriptFlags::BrowserExtended` flag.
+    // Keep the Annex B. behavior behind a flag, the users can enable it by passing the `ECMAScriptFlags::BrowserExtended` flag.
     bool m_should_use_browser_extended_grammar { false };
 
     // ECMA-262 basically requires that we clear the inner captures of a capture group before trying to match it,

Userland/Libraries/LibWasm/AbstractMachine/BytecodeInterpreter.cpp

@@ -307,7 +307,7 @@ template<typename V, typename T>
 MakeSigned<T> BytecodeInterpreter::checked_signed_truncate(V value)
 {
     if (isnan(value) || isinf(value)) { // "undefined", let's just trap.
-        m_trap = Trap { "Signed truncation undefined behaviour" };
+        m_trap = Trap { "Signed truncation undefined behavior" };
         return 0;
     }
 
@@ -330,7 +330,7 @@ template<typename V, typename T>
 MakeUnsigned<T> BytecodeInterpreter::checked_unsigned_truncate(V value)
 {
     if (isnan(value) || isinf(value)) { // "undefined", let's just trap.
-        m_trap = Trap { "Unsigned truncation undefined behaviour" };
+        m_trap = Trap { "Unsigned truncation undefined behavior" };
         return 0;
     }
     double truncated;

Userland/Libraries/LibWasm/AbstractMachine/Operators.h

@@ -317,7 +317,7 @@ struct CheckedTruncate {
     AK::Result<ResultT, StringView> operator()(Lhs lhs) const
     {
         if (isnan(lhs) || isinf(lhs)) // "undefined", let's just trap.
-            return "Truncation undefined behaviour"sv;
+            return "Truncation undefined behavior"sv;
 
         Lhs truncated;
         if constexpr (IsSame<float, Lhs>)

Userland/Libraries/LibWeb/DOM/EventDispatcher.cpp

@@ -181,7 +181,7 @@ bool EventDispatcher::dispatch(NonnullRefPtr<EventTarget> target, NonnullRefPtr<
 
         bool is_activation_event = is<UIEvents::MouseEvent>(*event) && event->type() == HTML::EventNames::click;
 
-        if (is_activation_event && target->activation_behaviour)
+        if (is_activation_event && target->activation_behavior)
             activation_target = target;
 
         // FIXME: Let slottable be target, if target is a slottable and is assigned, and null otherwise.
@@ -203,7 +203,7 @@ bool EventDispatcher::dispatch(NonnullRefPtr<EventTarget> target, NonnullRefPtr<
 
             if (is<Window>(parent)
                 || (is<Node>(parent) && verify_cast<Node>(*target).root().is_shadow_including_inclusive_ancestor_of(verify_cast<Node>(*parent)))) {
-                if (is_activation_event && event->bubbles() && !activation_target && parent->activation_behaviour)
+                if (is_activation_event && event->bubbles() && !activation_target && parent->activation_behavior)
                     activation_target = parent;
 
                 event->append_to_path(*parent, nullptr, related_target, touch_targets, slot_in_closed_tree);
@@ -212,7 +212,7 @@ bool EventDispatcher::dispatch(NonnullRefPtr<EventTarget> target, NonnullRefPtr<
             } else {
                 target = *parent;
 
-                if (is_activation_event && !activation_target && target->activation_behaviour)
+                if (is_activation_event && !activation_target && target->activation_behavior)
                     activation_target = target;
 
                 event->append_to_path(*parent, target, related_target, touch_targets, slot_in_closed_tree);
@@ -255,8 +255,8 @@ bool EventDispatcher::dispatch(NonnullRefPtr<EventTarget> target, NonnullRefPtr<
             }
         }
 
-        if (activation_target && activation_target->legacy_pre_activation_behaviour)
-            activation_target->legacy_pre_activation_behaviour();
+        if (activation_target && activation_target->legacy_pre_activation_behavior)
+            activation_target->legacy_pre_activation_behavior();
 
         for (ssize_t i = event->path().size() - 1; i >= 0; --i) {
             auto& entry = event->path().at(i);
@@ -298,11 +298,11 @@ bool EventDispatcher::dispatch(NonnullRefPtr<EventTarget> target, NonnullRefPtr<
 
     if (activation_target) {
         if (!event->cancelled()) {
-            // NOTE: Since activation_target is set, it will have activation behaviour.
-            activation_target->activation_behaviour(event);
+            // NOTE: Since activation_target is set, it will have activation behavior.
+            activation_target->activation_behavior(event);
         } else {
-            if (activation_target->legacy_cancelled_activation_behaviour)
-                activation_target->legacy_cancelled_activation_behaviour();
+            if (activation_target->legacy_cancelled_activation_behavior)
+                activation_target->legacy_cancelled_activation_behavior();
         }
     }
 

Userland/Libraries/LibWeb/DOM/EventTarget.h

@@ -47,11 +47,11 @@ public:
     Vector<EventListenerRegistration>& listeners() { return m_listeners; }
     const Vector<EventListenerRegistration>& listeners() const { return m_listeners; }
 
-    Function<void(const Event&)> activation_behaviour;
+    Function<void(const Event&)> activation_behavior;
 
     // NOTE: These only exist for checkbox and radio input elements.
-    Function<void()> legacy_pre_activation_behaviour;
-    Function<void()> legacy_cancelled_activation_behaviour;
+    Function<void()> legacy_pre_activation_behavior;
+    Function<void()> legacy_cancelled_activation_behavior;
 
 protected:
     explicit EventTarget(Bindings::ScriptExecutionContext&);

Userland/Libraries/LibWeb/HTML/AttributeNames.h

@@ -27,7 +27,7 @@ namespace AttributeNames {
     __ENUMERATE_HTML_ATTRIBUTE(autoplay)                   \
     __ENUMERATE_HTML_ATTRIBUTE(axis)                       \
     __ENUMERATE_HTML_ATTRIBUTE(background)                 \
-    __ENUMERATE_HTML_ATTRIBUTE(behaviour)                  \
+    __ENUMERATE_HTML_ATTRIBUTE(behavior)                   \
     __ENUMERATE_HTML_ATTRIBUTE(bgcolor)                    \
     __ENUMERATE_HTML_ATTRIBUTE(border)                     \
     __ENUMERATE_HTML_ATTRIBUTE(cellpadding)                \

Userland/Libraries/LibWeb/HTML/HTMLMarqueeElement.idl

@@ -1,6 +1,6 @@
 interface HTMLMarqueeElement : HTMLElement {
 
-    [Reflect] attribute DOMString behaviour;
+    [Reflect] attribute DOMString behavior;
     [Reflect=bgcolor] attribute DOMString bgColor;
     [Reflect] attribute DOMString direction;
     [Reflect] attribute DOMString height;