diff --git a/pom.xml b/pom.xml
index cbdcac32..60ea1466 100644
--- a/pom.xml
+++ b/pom.xml
@@ -69,6 +69,7 @@
         <module>io</module>
         <module>net</module>
         <module>os</module>
+        <module>ref</module>
         <module>version</module>
         <module>vertx-context</module>
     </modules>
diff --git a/ref/pom.xml b/ref/pom.xml
new file mode 100644
index 00000000..918b8d17
--- /dev/null
+++ b/ref/pom.xml
@@ -0,0 +1,49 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>io.smallrye.common</groupId>
+        <artifactId>smallrye-common-parent</artifactId>
+        <version>1.10.1-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>smallrye-common-ref</artifactId>
+
+    <name>SmallRye Common: References</name>
+
+    <dependencies>
+        <dependency>
+            <groupId>${project.groupId}</groupId>
+            <artifactId>smallrye-common-constraint</artifactId>
+        </dependency>
+    </dependencies>
+
+    <profiles>
+        <profile>
+            <id>coverage</id>
+            <properties>
+                <argLine>@{jacocoArgLine}</argLine>
+            </properties>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.jacoco</groupId>
+                        <artifactId>jacoco-maven-plugin</artifactId>
+                        <executions>
+                            <execution>
+                                <id>report</id>
+                                <phase>verify</phase>
+                                <goals>
+                                    <goal>report</goal>
+                                </goals>
+                            </execution>
+                        </executions>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+    </profiles>
+</project>
diff --git a/ref/src/main/java/io/smallrye/common/ref/CleanerReference.java b/ref/src/main/java/io/smallrye/common/ref/CleanerReference.java
new file mode 100644
index 00000000..0142744a
--- /dev/null
+++ b/ref/src/main/java/io/smallrye/common/ref/CleanerReference.java
@@ -0,0 +1,37 @@
+package io.smallrye.common.ref;
+
+import java.util.Collections;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * A special version of {@link PhantomReference} that is strongly retained until it is reaped by the collection thread.
+ */
+public class CleanerReference<T, A> extends PhantomReference<T, A> {
+    private static final Set<CleanerReference<?, ?>> set = Collections
+            .newSetFromMap(new ConcurrentHashMap<CleanerReference<?, ?>, Boolean>());
+
+    /**
+     * Construct a new instance with a reaper.
+     *
+     * @param referent the referent
+     * @param attachment the attachment
+     * @param reaper the reaper to use
+     */
+    public CleanerReference(final T referent, final A attachment, final Reaper<T, A> reaper) {
+        super(referent, attachment, reaper);
+        set.add(this);
+    }
+
+    void clean() {
+        set.remove(this);
+    }
+
+    public final int hashCode() {
+        return super.hashCode();
+    }
+
+    public final boolean equals(final Object obj) {
+        return super.equals(obj);
+    }
+}
diff --git a/ref/src/main/java/io/smallrye/common/ref/PhantomReference.java b/ref/src/main/java/io/smallrye/common/ref/PhantomReference.java
new file mode 100644
index 00000000..67722743
--- /dev/null
+++ b/ref/src/main/java/io/smallrye/common/ref/PhantomReference.java
@@ -0,0 +1,59 @@
+package io.smallrye.common.ref;
+
+import java.lang.ref.ReferenceQueue;
+
+/**
+ * A reapable phantom reference with an attachment. If a {@link Reaper} is given, then it will be used to asynchronously
+ * clean up the referent.
+ *
+ * @param <T> the reference value type
+ * @param <A> the attachment type
+ *
+ * @see java.lang.ref.PhantomReference
+ */
+public class PhantomReference<T, A> extends java.lang.ref.PhantomReference<T> implements Reference<T, A>, Reapable<T, A> {
+    private final A attachment;
+    private final Reaper<T, A> reaper;
+
+    /**
+     * Construct a new instance with an explicit reference queue.
+     *
+     * @param referent the referent
+     * @param attachment the attachment
+     * @param q the reference queue to use
+     */
+    public PhantomReference(final T referent, final A attachment, final ReferenceQueue<? super T> q) {
+        super(referent, q);
+        this.attachment = attachment;
+        reaper = null;
+    }
+
+    /**
+     * Construct a new instance with a reaper.
+     *
+     * @param referent the referent
+     * @param attachment the attachment
+     * @param reaper the reaper to use
+     */
+    public PhantomReference(final T referent, final A attachment, final Reaper<T, A> reaper) {
+        super(referent, References.ReaperThread.REAPER_QUEUE);
+        this.reaper = reaper;
+        this.attachment = attachment;
+    }
+
+    public A getAttachment() {
+        return attachment;
+    }
+
+    public Type getType() {
+        return Type.PHANTOM;
+    }
+
+    public Reaper<T, A> getReaper() {
+        return reaper;
+    }
+
+    public String toString() {
+        return "phantom reference";
+    }
+}
diff --git a/ref/src/main/java/io/smallrye/common/ref/Reapable.java b/ref/src/main/java/io/smallrye/common/ref/Reapable.java
new file mode 100644
index 00000000..216c9bf8
--- /dev/null
+++ b/ref/src/main/java/io/smallrye/common/ref/Reapable.java
@@ -0,0 +1,17 @@
+package io.smallrye.common.ref;
+
+/**
+ * A reference which is reapable (can be automatically collected).
+ *
+ * @param <T> the reference type
+ * @param <A> the reference attachment type
+ */
+interface Reapable<T, A> {
+
+    /**
+     * Get the associated reaper.
+     *
+     * @return the reaper
+     */
+    Reaper<T, A> getReaper();
+}
diff --git a/ref/src/main/java/io/smallrye/common/ref/Reaper.java b/ref/src/main/java/io/smallrye/common/ref/Reaper.java
new file mode 100644
index 00000000..a07b7dd7
--- /dev/null
+++ b/ref/src/main/java/io/smallrye/common/ref/Reaper.java
@@ -0,0 +1,17 @@
+package io.smallrye.common.ref;
+
+/**
+ * A cleaner for a dead object.
+ *
+ * @param <T> the reference type
+ * @param <A> the reference attachment type
+ */
+public interface Reaper<T, A> {
+
+    /**
+     * Perform the cleanup action for a reference.
+     *
+     * @param reference the reference
+     */
+    void reap(Reference<T, A> reference);
+}
diff --git a/ref/src/main/java/io/smallrye/common/ref/Reference.java b/ref/src/main/java/io/smallrye/common/ref/Reference.java
new file mode 100644
index 00000000..2365c7c6
--- /dev/null
+++ b/ref/src/main/java/io/smallrye/common/ref/Reference.java
@@ -0,0 +1,135 @@
+package io.smallrye.common.ref;
+
+import java.util.EnumSet;
+
+/**
+ * An enhanced reference type with a type-safe attachment.
+ *
+ * @param <T> the reference value type
+ * @param <A> the attachment type
+ *
+ * @see java.lang.ref.Reference
+ */
+public interface Reference<T, A> {
+
+    /**
+     * Get the value, or {@code null} if the reference has been cleared.
+     *
+     * @return the value
+     */
+    T get();
+
+    /**
+     * Get the attachment, if any.
+     *
+     * @return the attachment
+     */
+    A getAttachment();
+
+    /**
+     * Clear the reference.
+     */
+    void clear();
+
+    /**
+     * Get the type of the reference.
+     *
+     * @return the type
+     */
+    Type getType();
+
+    /**
+     * A reference type.
+     *
+     * @apiviz.exclude
+     */
+    enum Type {
+
+        /**
+         * A strong reference.
+         */
+        STRONG,
+        /**
+         * A weak reference.
+         */
+        WEAK,
+        /**
+         * A phantom reference.
+         */
+        PHANTOM,
+        /**
+         * A soft reference.
+         */
+        SOFT,
+        /**
+         * A {@code null} reference.
+         */
+        NULL,
+        ;
+
+        private static final int fullSize = values().length;
+
+        /**
+         * Determine whether the given set is fully populated (or "full"), meaning it contains all possible values.
+         *
+         * @param set the set
+         *
+         * @return {@code true} if the set is full, {@code false} otherwise
+         */
+        public static boolean isFull(final EnumSet<Type> set) {
+            return set != null && set.size() == fullSize;
+        }
+
+        /**
+         * Determine whether this instance is equal to one of the given instances.
+         *
+         * @param v1 the first instance
+         *
+         * @return {@code true} if one of the instances matches this one, {@code false} otherwise
+         */
+        public boolean in(final Type v1) {
+            return this == v1;
+        }
+
+        /**
+         * Determine whether this instance is equal to one of the given instances.
+         *
+         * @param v1 the first instance
+         * @param v2 the second instance
+         *
+         * @return {@code true} if one of the instances matches this one, {@code false} otherwise
+         */
+        public boolean in(final Type v1, final Type v2) {
+            return this == v1 || this == v2;
+        }
+
+        /**
+         * Determine whether this instance is equal to one of the given instances.
+         *
+         * @param v1 the first instance
+         * @param v2 the second instance
+         * @param v3 the third instance
+         *
+         * @return {@code true} if one of the instances matches this one, {@code false} otherwise
+         */
+        public boolean in(final Type v1, final Type v2, final Type v3) {
+            return this == v1 || this == v2 || this == v3;
+        }
+
+        /**
+         * Determine whether this instance is equal to one of the given instances.
+         *
+         * @param values the possible values
+         *
+         * @return {@code true} if one of the instances matches this one, {@code false} otherwise
+         */
+        public boolean in(final Type... values) {
+            if (values != null)
+                for (Type value : values) {
+                    if (this == value)
+                        return true;
+                }
+            return false;
+        }
+    }
+}
diff --git a/ref/src/main/java/io/smallrye/common/ref/References.java b/ref/src/main/java/io/smallrye/common/ref/References.java
new file mode 100644
index 00000000..1ac18f1b
--- /dev/null
+++ b/ref/src/main/java/io/smallrye/common/ref/References.java
@@ -0,0 +1,176 @@
+package io.smallrye.common.ref;
+
+import static java.security.AccessController.doPrivileged;
+
+import java.lang.ref.ReferenceQueue;
+import java.security.PrivilegedAction;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import io.smallrye.common.constraint.Assert;
+
+/**
+ * A set of utility methods for reference types.
+ */
+public final class References {
+    private References() {
+    }
+
+    private static final Reference<?, ?> NULL = new StrongReference<>(null);
+
+    static final class ReaperThread extends Thread {
+        static final ReferenceQueue<Object> REAPER_QUEUE = new ReferenceQueue<Object>();
+
+        static {
+            final AtomicInteger cnt = new AtomicInteger(1);
+            final PrivilegedAction<Void> action = () -> {
+                final ReaperThread thr = new ReaperThread();
+                thr.setName("Reference Reaper #" + cnt.getAndIncrement());
+                thr.setDaemon(true);
+                thr.start();
+                return null;
+            };
+            for (int i = 0; i < 3; i++) {
+                doPrivileged(action);
+            }
+        }
+
+        public void run() {
+            for (;;)
+                try {
+                    final java.lang.ref.Reference<?> ref = REAPER_QUEUE.remove();
+                    if (ref instanceof CleanerReference) {
+                        ((CleanerReference<?, ?>) ref).clean();
+                    }
+                    if (ref instanceof Reapable) {
+                        reap((Reapable<?, ?>) ref);
+                    }
+                } catch (InterruptedException ignored) {
+                    // we consume interrupts.
+                } catch (Throwable cause) {
+                    // ignore failures.
+                }
+        }
+
+        @SuppressWarnings({ "unchecked" })
+        private static <T, A> void reap(final Reapable<T, A> reapable) {
+            reapable.getReaper().reap((Reference<T, A>) reapable);
+        }
+    }
+
+    /**
+     * Create a reference of a given type with the provided value and attachment. If the reference type is
+     * {@link Reference.Type#STRONG} or {@link Reference.Type#NULL} then the reaper argument is ignored. If
+     * the reference type is {@link Reference.Type#NULL} then the value and attachment arguments are ignored.
+     *
+     * @param type the reference type
+     * @param value the reference value
+     * @param attachment the attachment value
+     * @param reaper the reaper to use, if any
+     * @param <T> the reference value type
+     * @param <A> the reference attachment type
+     * @return the reference
+     */
+    public static <T, A> Reference<T, A> create(Reference.Type type, T value, A attachment, Reaper<T, A> reaper) {
+        Assert.checkNotNullParam("type", type);
+        if (value == null) {
+            type = Reference.Type.NULL;
+        }
+        switch (type) {
+            case STRONG:
+                return new StrongReference<T, A>(value, attachment);
+            case WEAK:
+                return new WeakReference<T, A>(value, attachment, reaper);
+            case PHANTOM:
+                return new PhantomReference<T, A>(value, attachment, reaper);
+            case SOFT:
+                return new SoftReference<T, A>(value, attachment, reaper);
+            case NULL:
+                return attachment == null ? getNullReference() : new StrongReference<>(null, attachment);
+            default:
+                throw Assert.impossibleSwitchCase(type);
+        }
+    }
+
+    /**
+     * Create a reference of a given type with the provided value and attachment. If the reference type is
+     * {@link Reference.Type#STRONG} or {@link Reference.Type#NULL} then the reference queue argument is ignored. If
+     * the reference type is {@link Reference.Type#NULL} then the value and attachment arguments are ignored.
+     *
+     * @param type the reference type
+     * @param value the reference value
+     * @param attachment the attachment value
+     * @param referenceQueue the reference queue to use, if any
+     * @param <T> the reference value type
+     * @param <A> the reference attachment type
+     * @return the reference
+     */
+    public static <T, A> Reference<T, A> create(Reference.Type type, T value, A attachment,
+            ReferenceQueue<? super T> referenceQueue) {
+        Assert.checkNotNullParam("type", type);
+        if (referenceQueue == null)
+            return create(type, value, attachment);
+        if (value == null) {
+            type = Reference.Type.NULL;
+        }
+        switch (type) {
+            case STRONG:
+                return new StrongReference<T, A>(value, attachment);
+            case WEAK:
+                return new WeakReference<T, A>(value, attachment, referenceQueue);
+            case PHANTOM:
+                return new PhantomReference<T, A>(value, attachment, referenceQueue);
+            case SOFT:
+                return new SoftReference<T, A>(value, attachment, referenceQueue);
+            case NULL:
+                return attachment == null ? getNullReference() : new StrongReference<>(null, attachment);
+            default:
+                throw Assert.impossibleSwitchCase(type);
+        }
+    }
+
+    /**
+     * Create a reference of a given type with the provided value and attachment. If the reference type is
+     * {@link Reference.Type#PHANTOM} then this method will return a {@code null} reference because
+     * such references are not constructable without a queue or reaper. If the reference type is
+     * {@link Reference.Type#NULL} then the value and attachment arguments are ignored.
+     *
+     * @param type the reference type
+     * @param value the reference value
+     * @param attachment the attachment value
+     * @param <T> the reference value type
+     * @param <A> the reference attachment type
+     * @return the reference
+     */
+    public static <T, A> Reference<T, A> create(Reference.Type type, T value, A attachment) {
+        Assert.checkNotNullParam("type", type);
+        if (value == null) {
+            type = Reference.Type.NULL;
+        }
+        switch (type) {
+            case STRONG:
+                return new StrongReference<T, A>(value, attachment);
+            case WEAK:
+                return new WeakReference<T, A>(value, attachment);
+            case SOFT:
+                return new SoftReference<T, A>(value, attachment);
+            case PHANTOM:
+            case NULL:
+                return attachment == null ? getNullReference() : new StrongReference<>(null, attachment);
+            default:
+                throw Assert.impossibleSwitchCase(type);
+        }
+    }
+
+    /**
+     * Get a {@code null} reference. This reference type is always cleared and does not retain an attachment; as such
+     * there is only one single instance of it.
+     *
+     * @param <T> the reference value type
+     * @param <A> the attachment value type
+     * @return the {@code null} reference
+     */
+    @SuppressWarnings({ "unchecked" })
+    public static <T, A> Reference<T, A> getNullReference() {
+        return (Reference<T, A>) NULL;
+    }
+}
diff --git a/ref/src/main/java/io/smallrye/common/ref/SoftReference.java b/ref/src/main/java/io/smallrye/common/ref/SoftReference.java
new file mode 100644
index 00000000..93b82209
--- /dev/null
+++ b/ref/src/main/java/io/smallrye/common/ref/SoftReference.java
@@ -0,0 +1,78 @@
+package io.smallrye.common.ref;
+
+import java.lang.ref.ReferenceQueue;
+
+/**
+ * A reapable soft reference with an attachment. If a {@link Reaper} is given, then it will be used to asynchronously
+ * clean up the referent.
+ *
+ * @param <T> the reference value type
+ * @param <A> the attachment type
+ *
+ * @see java.lang.ref.SoftReference
+ */
+public class SoftReference<T, A> extends java.lang.ref.SoftReference<T> implements Reference<T, A>, Reapable<T, A> {
+    private final A attachment;
+    private final Reaper<T, A> reaper;
+
+    /**
+     * Construct a new instance.
+     *
+     * @param referent the referent
+     */
+    public SoftReference(final T referent) {
+        this(referent, null, (ReferenceQueue<T>) null);
+    }
+
+    /**
+     * Construct a new instance.
+     *
+     * @param referent the referent
+     * @param attachment the attachment
+     */
+    public SoftReference(final T referent, final A attachment) {
+        this(referent, attachment, (ReferenceQueue<T>) null);
+    }
+
+    /**
+     * Construct a new instance with an explicit reference queue.
+     *
+     * @param referent the referent
+     * @param attachment the attachment
+     * @param q the reference queue to use
+     */
+    public SoftReference(final T referent, final A attachment, final ReferenceQueue<? super T> q) {
+        super(referent, q);
+        reaper = null;
+        this.attachment = attachment;
+    }
+
+    /**
+     * Construct a new instance with a reaper.
+     *
+     * @param referent the referent
+     * @param attachment the attachment
+     * @param reaper the reaper to use
+     */
+    public SoftReference(final T referent, final A attachment, final Reaper<T, A> reaper) {
+        super(referent, References.ReaperThread.REAPER_QUEUE);
+        this.reaper = reaper;
+        this.attachment = attachment;
+    }
+
+    public Reaper<T, A> getReaper() {
+        return reaper;
+    }
+
+    public A getAttachment() {
+        return attachment;
+    }
+
+    public Type getType() {
+        return Type.SOFT;
+    }
+
+    public String toString() {
+        return "soft reference to " + get();
+    }
+}
diff --git a/ref/src/main/java/io/smallrye/common/ref/StrongReference.java b/ref/src/main/java/io/smallrye/common/ref/StrongReference.java
new file mode 100644
index 00000000..bf312d2b
--- /dev/null
+++ b/ref/src/main/java/io/smallrye/common/ref/StrongReference.java
@@ -0,0 +1,53 @@
+package io.smallrye.common.ref;
+
+/**
+ * A strong reference with an attachment. Since strong references are always reachable, a reaper may not be used.
+ *
+ * @param <T> the reference value type
+ * @param <A> the attachment type
+ */
+public class StrongReference<T, A> implements Reference<T, A> {
+
+    private volatile T referent;
+    private final A attachment;
+
+    /**
+     * Construct a new instance.
+     *
+     * @param referent the referent
+     * @param attachment the attachment
+     */
+    public StrongReference(final T referent, final A attachment) {
+        this.referent = referent;
+        this.attachment = attachment;
+    }
+
+    /**
+     * Construct a new instance.
+     *
+     * @param referent the referent
+     */
+    public StrongReference(final T referent) {
+        this(referent, null);
+    }
+
+    public T get() {
+        return referent;
+    }
+
+    public void clear() {
+        referent = null;
+    }
+
+    public A getAttachment() {
+        return attachment;
+    }
+
+    public Type getType() {
+        return Type.STRONG;
+    }
+
+    public String toString() {
+        return "strong reference to " + get();
+    }
+}
diff --git a/ref/src/main/java/io/smallrye/common/ref/WeakReference.java b/ref/src/main/java/io/smallrye/common/ref/WeakReference.java
new file mode 100644
index 00000000..688970a2
--- /dev/null
+++ b/ref/src/main/java/io/smallrye/common/ref/WeakReference.java
@@ -0,0 +1,78 @@
+package io.smallrye.common.ref;
+
+import java.lang.ref.ReferenceQueue;
+
+/**
+ * A reapable weak reference with an attachment. If a {@link Reaper} is given, then it will be used to asynchronously
+ * clean up the referent.
+ *
+ * @param <T> the reference value type
+ * @param <A> the attachment type
+ *
+ * @see java.lang.ref.WeakReference
+ */
+public class WeakReference<T, A> extends java.lang.ref.WeakReference<T> implements Reference<T, A>, Reapable<T, A> {
+    private final A attachment;
+    private final Reaper<T, A> reaper;
+
+    /**
+     * Construct a new instance.
+     *
+     * @param referent the referent
+     */
+    public WeakReference(final T referent) {
+        this(referent, null, (Reaper<T, A>) null);
+    }
+
+    /**
+     * Construct a new instance.
+     *
+     * @param referent the referent
+     * @param attachment the attachment
+     */
+    public WeakReference(final T referent, final A attachment) {
+        this(referent, attachment, (Reaper<T, A>) null);
+    }
+
+    /**
+     * Construct a new instance with an explicit reference queue.
+     *
+     * @param referent the referent
+     * @param attachment the attachment
+     * @param q the reference queue to use
+     */
+    public WeakReference(final T referent, final A attachment, final ReferenceQueue<? super T> q) {
+        super(referent, q);
+        this.attachment = attachment;
+        reaper = null;
+    }
+
+    /**
+     * Construct a new instance with a reaper.
+     *
+     * @param referent the referent
+     * @param attachment the attachment
+     * @param reaper the reaper to use
+     */
+    public WeakReference(final T referent, final A attachment, final Reaper<T, A> reaper) {
+        super(referent, References.ReaperThread.REAPER_QUEUE);
+        this.attachment = attachment;
+        this.reaper = reaper;
+    }
+
+    public A getAttachment() {
+        return attachment;
+    }
+
+    public Type getType() {
+        return Type.WEAK;
+    }
+
+    public Reaper<T, A> getReaper() {
+        return reaper;
+    }
+
+    public String toString() {
+        return "weak reference to " + get();
+    }
+}
diff --git a/ref/src/main/java/io/smallrye/common/ref/package-info.java b/ref/src/main/java/io/smallrye/common/ref/package-info.java
new file mode 100644
index 00000000..ce13421f
--- /dev/null
+++ b/ref/src/main/java/io/smallrye/common/ref/package-info.java
@@ -0,0 +1,6 @@
+/**
+ * Classes which implement reference types which can be cleaned up automatically by a background thread. See
+ * {@link io.smallrye.common.ref.Reference Reference} and its subtypes, and {@link io.smallrye.common.ref.Reaper Reaper} for
+ * more information.
+ */
+package io.smallrye.common.ref;
\ No newline at end of file