diff --git a/components/script/dom/element.rs b/components/script/dom/element.rs
index dcafd4bf9d7..3c94ca21339 100644
--- a/components/script/dom/element.rs
+++ b/components/script/dom/element.rs
@@ -86,7 +86,7 @@ use parking_lot::RwLock;
 use ref_filter_map::ref_filter_map;
 use script_layout_interface::message::ReflowQueryType;
 use script_thread::Runnable;
-use selectors::matching::{ElementSelectorFlags, matches};
+use selectors::matching::{ElementSelectorFlags, StyleRelations, matches};
 use selectors::matching::{HAS_EDGE_CHILD_SELECTOR, HAS_SLOW_SELECTOR, HAS_SLOW_SELECTOR_LATER_SIBLINGS};
 use selectors::parser::{AttrSelector, NamespaceConstraint};
 use servo_atoms::Atom;
@@ -2392,7 +2392,10 @@ impl<'a> ::selectors::Element for Root<Element> {
         self.namespace()
     }
 
-    fn match_non_ts_pseudo_class(&self, pseudo_class: &NonTSPseudoClass) -> bool {
+    fn match_non_ts_pseudo_class(&self,
+                                 pseudo_class: &NonTSPseudoClass,
+                                 _: &mut StyleRelations,
+                                 _: &mut ElementSelectorFlags) -> bool {
         match *pseudo_class {
             // https://github.com/servo/servo/issues/8718
             NonTSPseudoClass::Link |
diff --git a/components/script/layout_wrapper.rs b/components/script/layout_wrapper.rs
index b8a38247fd7..98ce86745f2 100644
--- a/components/script/layout_wrapper.rs
+++ b/components/script/layout_wrapper.rs
@@ -50,7 +50,7 @@ use script_layout_interface::{HTMLCanvasData, LayoutNodeType, SVGSVGData, Truste
 use script_layout_interface::{OpaqueStyleAndLayoutData, PartialPersistentLayoutData};
 use script_layout_interface::wrapper_traits::{DangerousThreadSafeLayoutNode, GetLayoutData, LayoutNode};
 use script_layout_interface::wrapper_traits::{PseudoElementType, ThreadSafeLayoutElement, ThreadSafeLayoutNode};
-use selectors::matching::ElementSelectorFlags;
+use selectors::matching::{ElementSelectorFlags, StyleRelations};
 use selectors::parser::{AttrSelector, NamespaceConstraint};
 use servo_atoms::Atom;
 use servo_url::ServoUrl;
@@ -611,7 +611,10 @@ impl<'le> ::selectors::Element for ServoLayoutElement<'le> {
         self.element.namespace()
     }
 
-    fn match_non_ts_pseudo_class(&self, pseudo_class: &NonTSPseudoClass) -> bool {
+    fn match_non_ts_pseudo_class(&self,
+                                 pseudo_class: &NonTSPseudoClass,
+                                 _: &mut StyleRelations,
+                                 _: &mut ElementSelectorFlags) -> bool {
         match *pseudo_class {
             // https://github.com/servo/servo/issues/8718
             NonTSPseudoClass::Link |
@@ -1106,7 +1109,10 @@ impl<'le> ::selectors::Element for ServoThreadSafeLayoutElement<'le> {
         self.element.get_namespace()
     }
 
-    fn match_non_ts_pseudo_class(&self, _: &NonTSPseudoClass) -> bool {
+    fn match_non_ts_pseudo_class(&self,
+                                 _: &NonTSPseudoClass,
+                                 _: &mut StyleRelations,
+                                 _: &mut ElementSelectorFlags) -> bool {
         // NB: This could maybe be implemented
         warn!("ServoThreadSafeLayoutElement::match_non_ts_pseudo_class called");
         false
diff --git a/components/selectors/matching.rs b/components/selectors/matching.rs
index efe1d76007e..f567b2bc7ca 100644
--- a/components/selectors/matching.rs
+++ b/components/selectors/matching.rs
@@ -413,7 +413,7 @@ fn matches_simple_selector<E>(
             false
         }
         SimpleSelector::NonTSPseudoClass(ref pc) => {
-            relation_if!(element.match_non_ts_pseudo_class(pc),
+            relation_if!(element.match_non_ts_pseudo_class(pc, relations, flags),
                          AFFECTED_BY_STATE)
         }
         SimpleSelector::FirstChild => {
diff --git a/components/selectors/parser.rs b/components/selectors/parser.rs
index d5cae30042f..c921d1fb9b1 100644
--- a/components/selectors/parser.rs
+++ b/components/selectors/parser.rs
@@ -49,7 +49,7 @@ macro_rules! with_all_bounds {
 
             /// non tree-structural pseudo-classes
             /// (see: https://drafts.csswg.org/selectors/#structural-pseudos)
-            type NonTSPseudoClass: $($CommonBounds)* + Sized + ToCss;
+            type NonTSPseudoClass: $($CommonBounds)* + Sized + ToCss + SelectorMethods;
 
             /// pseudo-elements
             type PseudoElement: $($CommonBounds)* + Sized + ToCss;
@@ -120,7 +120,7 @@ pub trait Parser {
     }
 }
 
-#[derive(PartialEq, Clone, Debug)]
+#[derive(PartialEq, Eq, Hash, Clone, Debug)]
 pub struct SelectorList<Impl: SelectorImpl>(pub Vec<Selector<Impl>>);
 
 impl<Impl: SelectorImpl> SelectorList<Impl> {
@@ -135,7 +135,7 @@ impl<Impl: SelectorImpl> SelectorList<Impl> {
     }
 }
 
-#[derive(PartialEq, Clone)]
+#[derive(PartialEq, Eq, Hash, Clone)]
 pub struct Selector<Impl: SelectorImpl> {
     pub complex_selector: Arc<ComplexSelector<Impl>>,
     pub pseudo_element: Option<Impl::PseudoElement>,
@@ -159,6 +159,8 @@ fn affects_sibling<Impl: SelectorImpl>(simple_selector: &SimpleSelector<Impl>) -
         SimpleSelector::LastOfType |
         SimpleSelector::OnlyOfType => true,
 
+        SimpleSelector::NonTSPseudoClass(ref pseudo_class) => pseudo_class.affects_siblings(),
+
         _ => false,
     }
 }
@@ -180,28 +182,36 @@ fn matches_non_common_style_affecting_attribute<Impl: SelectorImpl>(simple_selec
         SimpleSelector::AttrSuffixMatch(..) |
         SimpleSelector::AttrSubstringMatch(..) => true,
 
+        SimpleSelector::NonTSPseudoClass(ref pseudo_class) =>
+            pseudo_class.matches_non_common_style_affecting_attribute(),
+
         // This deliberately includes Attr*NeverMatch
         // which never match regardless of element attributes.
         _ => false,
     }
 }
 
-impl<Impl: SelectorImpl> Selector<Impl> {
+pub trait SelectorMethods {
+    fn affects_siblings(&self) -> bool;
+    fn matches_non_common_style_affecting_attribute(&self) -> bool;
+}
+
+impl<Impl: SelectorImpl> SelectorMethods for Selector<Impl> {
     /// Whether this selector, if matching on a set of siblings, could affect
     /// other sibling's style.
-    pub fn affects_siblings(&self) -> bool {
+    fn affects_siblings(&self) -> bool {
         self.complex_selector.affects_siblings()
     }
 
-    pub fn matches_non_common_style_affecting_attribute(&self) -> bool {
+    fn matches_non_common_style_affecting_attribute(&self) -> bool {
         self.complex_selector.matches_non_common_style_affecting_attribute()
     }
 }
 
-impl<Impl: SelectorImpl> ComplexSelector<Impl> {
+impl<Impl: SelectorImpl> SelectorMethods for ComplexSelector<Impl> {
     /// Whether this complex selector, if matching on a set of siblings,
     /// could affect other sibling's style.
-    pub fn affects_siblings(&self) -> bool {
+    fn affects_siblings(&self) -> bool {
         match self.next {
             Some((_, Combinator::NextSibling)) |
             Some((_, Combinator::LaterSibling)) => return true,
@@ -214,7 +224,7 @@ impl<Impl: SelectorImpl> ComplexSelector<Impl> {
         }
     }
 
-    pub fn matches_non_common_style_affecting_attribute(&self) -> bool {
+    fn matches_non_common_style_affecting_attribute(&self) -> bool {
         match self.compound_selector.last() {
             Some(ref selector) => matches_non_common_style_affecting_attribute(selector),
             None => false,
@@ -714,18 +724,18 @@ fn parse_complex_selector_and_pseudo_element<P, Impl>(
     Ok((complex, pseudo_element))
 }
 
-fn parse_complex_selector<P, Impl>(
-        parser: &P,
-        input: &mut CssParser)
-        -> Result<ComplexSelector<Impl>, ()>
-    where P: Parser<Impl=Impl>, Impl: SelectorImpl
-{
-    let (complex, pseudo_element) =
-        parse_complex_selector_and_pseudo_element(parser, input)?;
-    if pseudo_element.is_some() {
-        return Err(())
+impl<Impl: SelectorImpl> ComplexSelector<Impl> {
+    /// Parse a complex selector.
+    pub fn parse<P>(parser: &P, input: &mut CssParser) -> Result<Self, ()>
+        where P: Parser<Impl=Impl>
+    {
+        let (complex, pseudo_element) =
+            parse_complex_selector_and_pseudo_element(parser, input)?;
+        if pseudo_element.is_some() {
+            return Err(())
+        }
+        Ok(complex)
     }
-    Ok(complex)
 }
 
 /// * `Err(())`: Invalid selector, abort
@@ -934,7 +944,7 @@ fn parse_negation<P, Impl>(parser: &P,
                            -> Result<SimpleSelector<Impl>, ()>
     where P: Parser<Impl=Impl>, Impl: SelectorImpl
 {
-    input.parse_comma_separated(|input| parse_complex_selector(parser, input).map(Arc::new))
+    input.parse_comma_separated(|input| ComplexSelector::parse(parser, input).map(Arc::new))
          .map(SimpleSelector::Negation)
 }
 
@@ -1164,6 +1174,11 @@ pub mod tests {
         }
     }
 
+    impl SelectorMethods for PseudoClass {
+        fn affects_siblings(&self) -> bool { false }
+        fn matches_non_common_style_affecting_attribute(&self) -> bool { false }
+    }
+
     #[derive(PartialEq, Debug)]
     pub struct DummySelectorImpl;
 
diff --git a/components/selectors/tree.rs b/components/selectors/tree.rs
index a76e1d577c8..315d9d7196d 100644
--- a/components/selectors/tree.rs
+++ b/components/selectors/tree.rs
@@ -5,6 +5,7 @@
 //! Traits that nodes must implement. Breaks the otherwise-cyclic dependency between layout and
 //! style.
 
+use matching::{ElementSelectorFlags, StyleRelations};
 use parser::{AttrSelector, SelectorImpl};
 use std::ascii::AsciiExt;
 
@@ -138,7 +139,10 @@ pub trait Element: MatchAttr + Sized {
     fn get_local_name(&self) -> &<Self::Impl as SelectorImpl>::BorrowedLocalName;
     fn get_namespace(&self) -> &<Self::Impl as SelectorImpl>::BorrowedNamespaceUrl;
 
-    fn match_non_ts_pseudo_class(&self, pc: &<Self::Impl as SelectorImpl>::NonTSPseudoClass) -> bool;
+    fn match_non_ts_pseudo_class(&self,
+                                 pc: &<Self::Impl as SelectorImpl>::NonTSPseudoClass,
+                                 relations: &mut StyleRelations,
+                                 flags: &mut ElementSelectorFlags) -> bool;
 
     fn get_id(&self) -> Option<<Self::Impl as SelectorImpl>::Identifier>;
     fn has_class(&self, name: &<Self::Impl as SelectorImpl>::ClassName) -> bool;
diff --git a/components/style/gecko/selector_parser.rs b/components/style/gecko/selector_parser.rs
index d465b7fa791..8b3b019dc77 100644
--- a/components/style/gecko/selector_parser.rs
+++ b/components/style/gecko/selector_parser.rs
@@ -8,9 +8,10 @@ use cssparser::{Parser, ToCss};
 use element_state::ElementState;
 use gecko_bindings::structs::CSSPseudoClassType;
 use gecko_bindings::structs::nsIAtom;
+use restyle_hints::complex_selector_to_state;
 use selector_parser::{SelectorParser, PseudoElementCascadeType};
 use selector_parser::{attr_equals_selector_is_shareable, attr_exists_selector_is_shareable};
-use selectors::parser::AttrSelector;
+use selectors::parser::{AttrSelector, ComplexSelector, SelectorMethods};
 use std::borrow::Cow;
 use std::fmt;
 use std::ptr;
@@ -152,6 +153,8 @@ macro_rules! pseudo_class_name {
                 #[doc = $s_css]
                 $s_name(Box<str>),
             )*
+            /// The non-standard `:-moz-any` pseudo-class.
+            MozAny(Vec<ComplexSelector<SelectorImpl>>),
         }
     }
 }
@@ -167,6 +170,17 @@ impl ToCss for NonTSPseudoClass {
                     $(NonTSPseudoClass::$s_name(ref s) => {
                         return dest.write_str(&format!(":{}({})", $s_css, s))
                     }, )*
+                    NonTSPseudoClass::MozAny(ref selectors) => {
+                        dest.write_str(":-moz-any(")?;
+                        let mut iter = selectors.iter();
+                        let first = iter.next().expect(":-moz-any must have at least 1 selector");
+                        first.to_css(dest)?;
+                        for selector in iter {
+                            dest.write_str(", ")?;
+                            selector.to_css(dest)?;
+                        }
+                        return dest.write_str(")")
+                    }
                 }
             }
         }
@@ -175,6 +189,29 @@ impl ToCss for NonTSPseudoClass {
     }
 }
 
+impl SelectorMethods for NonTSPseudoClass {
+    #[inline]
+    fn affects_siblings(&self) -> bool {
+        match *self {
+            NonTSPseudoClass::MozAny(ref selectors) => {
+                selectors.iter().any(|s| s.affects_siblings())
+            }
+            _ => false
+        }
+    }
+
+    #[inline]
+    fn matches_non_common_style_affecting_attribute(&self) -> bool {
+        match *self {
+            NonTSPseudoClass::MozAny(ref selectors) => {
+                selectors.iter().any(|s| s.matches_non_common_style_affecting_attribute())
+            }
+            _ => false
+        }
+    }
+}
+
+
 impl NonTSPseudoClass {
     /// A pseudo-class is internal if it can only be used inside
     /// user agent style sheets.
@@ -189,6 +226,7 @@ impl NonTSPseudoClass {
                 match *self {
                     $(NonTSPseudoClass::$name => check_flag!($flags),)*
                     $(NonTSPseudoClass::$s_name(..) => check_flag!($s_flags),)*
+                    NonTSPseudoClass::MozAny(_) => false,
                 }
             }
         }
@@ -207,6 +245,11 @@ impl NonTSPseudoClass {
                 match *self {
                     $(NonTSPseudoClass::$name => flag!($state),)*
                     $(NonTSPseudoClass::$s_name(..) => flag!($s_state),)*
+                    NonTSPseudoClass::MozAny(ref selectors) => {
+                        selectors.iter().fold(ElementState::empty(), |state, s| {
+                            state | complex_selector_to_state(s)
+                        })
+                    }
                 }
             }
         }
@@ -226,6 +269,7 @@ impl NonTSPseudoClass {
                 match *self {
                     $(NonTSPseudoClass::$name => gecko_type!($gecko_type),)*
                     $(NonTSPseudoClass::$s_name(..) => gecko_type!($s_gecko_type),)*
+                    NonTSPseudoClass::MozAny(_) => gecko_type!(any),
                 }
             }
         }
@@ -234,7 +278,7 @@ impl NonTSPseudoClass {
 }
 
 /// The dummy struct we use to implement our selector parsing.
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub struct SelectorImpl;
 
 impl ::selectors::SelectorImpl for SelectorImpl {
@@ -293,6 +337,12 @@ impl<'a> ::selectors::Parser for SelectorParser<'a> {
                         let name = String::from(parser.expect_ident_or_string()?).into_boxed_str();
                         NonTSPseudoClass::$s_name(name)
                     }, )*
+                    "-moz-any" => {
+                        let selectors = parser.parse_comma_separated(|input| {
+                            ComplexSelector::parse(self, input)
+                        })?;
+                        NonTSPseudoClass::MozAny(selectors)
+                    }
                     _ => return Err(())
                 }
             }
diff --git a/components/style/gecko/wrapper.rs b/components/style/gecko/wrapper.rs
index 76974f0d2f7..86ac901e407 100644
--- a/components/style/gecko/wrapper.rs
+++ b/components/style/gecko/wrapper.rs
@@ -49,7 +49,7 @@ use properties::PropertyDeclarationBlock;
 use rule_tree::CascadeLevel as ServoCascadeLevel;
 use selector_parser::{ElementExt, Snapshot};
 use selectors::Element;
-use selectors::matching::ElementSelectorFlags;
+use selectors::matching::{ElementSelectorFlags, StyleRelations, matches_complex_selector};
 use selectors::parser::{AttrSelector, NamespaceConstraint};
 use servo_url::ServoUrl;
 use sink::Push;
@@ -637,7 +637,10 @@ impl<'le> ::selectors::Element for GeckoElement<'le> {
         }
     }
 
-    fn match_non_ts_pseudo_class(&self, pseudo_class: &NonTSPseudoClass) -> bool {
+    fn match_non_ts_pseudo_class(&self,
+                                 pseudo_class: &NonTSPseudoClass,
+                                 relations: &mut StyleRelations,
+                                 flags: &mut ElementSelectorFlags) -> bool {
         match *pseudo_class {
             // https://github.com/servo/servo/issues/8718
             NonTSPseudoClass::AnyLink => unsafe { Gecko_IsLink(self.0) },
@@ -667,7 +670,10 @@ impl<'le> ::selectors::Element for GeckoElement<'le> {
             NonTSPseudoClass::MozBrowserFrame => unsafe {
                 Gecko_MatchesElement(pseudo_class.to_gecko_pseudoclasstype().unwrap(), self.0)
             },
-            _ => false
+            NonTSPseudoClass::MozSystemMetric(_) => false,
+            NonTSPseudoClass::MozAny(ref sels) => {
+                sels.iter().any(|s| matches_complex_selector(s, self, None, relations, flags))
+            }
         }
     }
 
@@ -805,7 +811,9 @@ impl<'le> ::selectors::MatchAttr for GeckoElement<'le> {
 impl<'le> ElementExt for GeckoElement<'le> {
     #[inline]
     fn is_link(&self) -> bool {
-        self.match_non_ts_pseudo_class(&NonTSPseudoClass::AnyLink)
+        self.match_non_ts_pseudo_class(&NonTSPseudoClass::AnyLink,
+                                       &mut StyleRelations::empty(),
+                                       &mut ElementSelectorFlags::empty())
     }
 
     #[inline]
diff --git a/components/style/restyle_hints.rs b/components/style/restyle_hints.rs
index 7b744284e0b..bfa47169783 100644
--- a/components/style/restyle_hints.rs
+++ b/components/style/restyle_hints.rs
@@ -269,14 +269,17 @@ impl<'a, E> MatchAttr for ElementWrapper<'a, E>
 impl<'a, E> Element for ElementWrapper<'a, E>
     where E: TElement,
 {
-    fn match_non_ts_pseudo_class(&self, pseudo_class: &NonTSPseudoClass) -> bool {
+    fn match_non_ts_pseudo_class(&self,
+                                 pseudo_class: &NonTSPseudoClass,
+                                 relations: &mut StyleRelations,
+                                 flags: &mut ElementSelectorFlags) -> bool {
         let flag = SelectorImpl::pseudo_class_state_flag(pseudo_class);
         if flag == ElementState::empty() {
-            self.element.match_non_ts_pseudo_class(pseudo_class)
+            self.element.match_non_ts_pseudo_class(pseudo_class, relations, flags)
         } else {
             match self.snapshot.and_then(|s| s.state()) {
                 Some(snapshot_state) => snapshot_state.contains(flag),
-                _   => self.element.match_non_ts_pseudo_class(pseudo_class)
+                _   => self.element.match_non_ts_pseudo_class(pseudo_class, relations, flags)
             }
         }
     }
@@ -347,6 +350,13 @@ impl<'a, E> Element for ElementWrapper<'a, E>
     }
 }
 
+/// Returns the union of any `ElementState` flags for components of a `ComplexSelector`
+pub fn complex_selector_to_state(sel: &ComplexSelector<SelectorImpl>) -> ElementState {
+    sel.compound_selector.iter().fold(ElementState::empty(), |state, s| {
+        state | selector_to_state(s)
+    })
+}
+
 fn selector_to_state(sel: &SimpleSelector<SelectorImpl>) -> ElementState {
     match *sel {
         SimpleSelector::NonTSPseudoClass(ref pc) => SelectorImpl::pseudo_class_state_flag(pc),
diff --git a/components/style/servo/selector_parser.rs b/components/style/servo/selector_parser.rs
index ab4c0b658f8..78601a9b0dd 100644
--- a/components/style/servo/selector_parser.rs
+++ b/components/style/servo/selector_parser.rs
@@ -14,7 +14,8 @@ use restyle_hints::ElementSnapshot;
 use selector_parser::{ElementExt, PseudoElementCascadeType, SelectorParser};
 use selector_parser::{attr_equals_selector_is_shareable, attr_exists_selector_is_shareable};
 use selectors::{Element, MatchAttrGeneric};
-use selectors::parser::AttrSelector;
+use selectors::matching::{ElementSelectorFlags, StyleRelations};
+use selectors::parser::{AttrSelector, SelectorMethods};
 use std::borrow::Cow;
 use std::fmt;
 use std::fmt::Debug;
@@ -60,7 +61,6 @@ impl ToCss for PseudoElement {
     }
 }
 
-
 impl PseudoElement {
     /// Whether the current pseudo element is :before or :after.
     #[inline]
@@ -150,6 +150,13 @@ impl ToCss for NonTSPseudoClass {
     }
 }
 
+impl SelectorMethods for NonTSPseudoClass {
+    #[inline]
+    fn affects_siblings(&self) -> bool { false }
+    #[inline]
+    fn matches_non_common_style_affecting_attribute(&self) -> bool { false }
+}
+
 impl NonTSPseudoClass {
     /// Gets a given state flag for this pseudo-class. This is used to do
     /// selector matching, and it's set from the DOM.
@@ -450,7 +457,9 @@ impl MatchAttrGeneric for ServoElementSnapshot {
 
 impl<E: Element<Impl=SelectorImpl> + Debug> ElementExt for E {
     fn is_link(&self) -> bool {
-        self.match_non_ts_pseudo_class(&NonTSPseudoClass::AnyLink)
+        self.match_non_ts_pseudo_class(&NonTSPseudoClass::AnyLink,
+                                       &mut StyleRelations::empty(),
+                                       &mut ElementSelectorFlags::empty())
     }
 
     #[inline]
diff --git a/components/style/stylist.rs b/components/style/stylist.rs
index 79044cd1fb5..f7dd149e7d3 100644
--- a/components/style/stylist.rs
+++ b/components/style/stylist.rs
@@ -27,6 +27,7 @@ use selectors::matching::{AFFECTED_BY_ANIMATIONS, AFFECTED_BY_TRANSITIONS};
 use selectors::matching::{AFFECTED_BY_STYLE_ATTRIBUTE, AFFECTED_BY_PRESENTATIONAL_HINTS};
 use selectors::matching::{ElementSelectorFlags, StyleRelations, matches_complex_selector};
 use selectors::parser::{Selector, SimpleSelector, LocalName as LocalNameSelector, ComplexSelector};
+use selectors::parser::SelectorMethods;
 use sink::Push;
 use smallvec::VecLike;
 use std::borrow::Borrow;