diff --git a/OpenRA.FileFormats/OpenRA.FileFormats.csproj b/OpenRA.FileFormats/OpenRA.FileFormats.csproj
index 02c58d7291..95e2f659fa 100644
--- a/OpenRA.FileFormats/OpenRA.FileFormats.csproj
+++ b/OpenRA.FileFormats/OpenRA.FileFormats.csproj
@@ -120,7 +120,10 @@
     <Compile Include="Primitives\Cache.cs" />
     <Compile Include="Primitives\Cached.cs" />
     <Compile Include="Primitives\DisposableAction.cs" />
+    <Compile Include="Primitives\IObservableCollection.cs" />
     <Compile Include="Primitives\Lazy.cs" />
+    <Compile Include="Primitives\ObservableCollection.cs" />
+    <Compile Include="Primitives\ObservableDictionary.cs" />
     <Compile Include="Primitives\Pair.cs" />
     <Compile Include="Primitives\PriorityQueue.cs" />
     <Compile Include="Primitives\Set.cs" />
diff --git a/OpenRA.FileFormats/Primitives/IObservableCollection.cs b/OpenRA.FileFormats/Primitives/IObservableCollection.cs
new file mode 100644
index 0000000000..f7da4fe6c3
--- /dev/null
+++ b/OpenRA.FileFormats/Primitives/IObservableCollection.cs
@@ -0,0 +1,25 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2013 The OpenRA Developers (see AUTHORS)
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation. For more information,
+ * see COPYING.
+ */
+#endregion
+
+using System;
+using System.Collections;
+
+namespace OpenRA.FileFormats.Primitives
+{
+	public interface IObservableCollection
+	{
+		event Action<object> OnAdd;
+		event Action<object> OnRemove;
+		event Action<int> OnRemoveAt;
+		event Action<object, object> OnSet;
+		event Action OnRefresh;
+		IEnumerable ObservedItems { get; }
+	}
+}
diff --git a/OpenRA.FileFormats/Primitives/ObservableCollection.cs b/OpenRA.FileFormats/Primitives/ObservableCollection.cs
new file mode 100644
index 0000000000..610cb28762
--- /dev/null
+++ b/OpenRA.FileFormats/Primitives/ObservableCollection.cs
@@ -0,0 +1,59 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2013 The OpenRA Developers (see AUTHORS)
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation. For more information,
+ * see COPYING.
+ */
+#endregion
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+
+namespace OpenRA.FileFormats.Primitives
+{
+	public class ObservableCollection<T> : Collection<T>, IObservableCollection
+	{
+		public event Action<object> OnAdd = k => { };
+		public event Action<object> OnRemove = k => { };
+		public event Action<int> OnRemoveAt = i => { };
+		public event Action<object, object> OnSet = (o, n) => { };
+		public event Action OnRefresh = () => { };
+
+		public ObservableCollection() : base() { }
+		public ObservableCollection(IList<T> list) : base(list) { }
+
+		protected override void SetItem(int index, T item)
+		{
+			var old = this[index];
+			base.SetItem(index, item);
+			OnSet(old, item);
+		}
+
+		protected override void InsertItem(int index, T item)
+		{
+			base.InsertItem(index, item);
+			OnAdd(item);
+		}
+
+		protected override void ClearItems()
+		{
+			base.ClearItems();
+			OnRefresh();
+		}
+
+		protected override void RemoveItem(int index)
+		{
+			base.RemoveItem(index);
+			OnRemoveAt(index);
+		}
+
+		public IEnumerable ObservedItems
+		{
+			get { return base.Items; }
+		}
+	}
+}
diff --git a/OpenRA.FileFormats/Primitives/ObservableDictionary.cs b/OpenRA.FileFormats/Primitives/ObservableDictionary.cs
new file mode 100644
index 0000000000..2f078cb451
--- /dev/null
+++ b/OpenRA.FileFormats/Primitives/ObservableDictionary.cs
@@ -0,0 +1,137 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2013 The OpenRA Developers (see AUTHORS)
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation. For more information,
+ * see COPYING.
+ */
+#endregion
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+
+namespace OpenRA.FileFormats.Primitives
+{
+	public class ObservableSortedDictionary<TKey, TValue> : ObservableDictionary<TKey, TValue>
+	{
+		public ObservableSortedDictionary(IComparer<TKey> comparer)
+		{
+			InnerDict = new SortedDictionary<TKey, TValue>(comparer);
+		}
+
+		public override void Add(TKey key, TValue value)
+		{
+			InnerDict.Add(key, value);
+			FireOnRefresh();
+		}
+	}
+
+	public class ObservableDictionary<TKey, TValue> : IDictionary<TKey, TValue>, IObservableCollection
+	{
+		protected IDictionary<TKey, TValue> InnerDict;
+
+		public event Action<object> OnAdd = k => { };
+		public event Action<object> OnRemove = k => { };
+		public event Action<int> OnRemoveAt = i => { };
+		public event Action<object, object> OnSet = (o, n) => { };
+		public event Action OnRefresh = () => { };
+
+		protected void FireOnRefresh()
+		{
+			OnRefresh();
+		}
+
+		protected ObservableDictionary() { }
+
+		public ObservableDictionary(IEqualityComparer<TKey> comparer)
+		{
+			InnerDict = new Dictionary<TKey, TValue>(comparer);
+		}
+
+		public virtual void Add(TKey key, TValue value)
+		{
+			InnerDict.Add(key, value);
+			OnAdd(key);
+		}
+
+		public bool Remove(TKey key)
+		{
+			var found = InnerDict.Remove(key);
+			if (found)
+				OnRemove(key);
+			return found;
+		}
+
+		public bool ContainsKey(TKey key)
+		{
+			return InnerDict.ContainsKey(key);
+		}
+
+		public ICollection<TKey> Keys { get { return InnerDict.Keys; } }
+		public ICollection<TValue> Values { get { return InnerDict.Values; } }
+
+		public bool TryGetValue(TKey key, out TValue value)
+		{
+			return InnerDict.TryGetValue(key, out value);
+		}
+
+		public TValue this[TKey key]
+		{
+			get { return InnerDict[key]; }
+			set { InnerDict[key] = value; }
+		}
+
+		public void Clear()
+		{
+			InnerDict.Clear();
+			OnRefresh();
+		}
+
+		public int Count
+		{
+			get { return InnerDict.Count; }
+		}
+
+		public void Add(KeyValuePair<TKey, TValue> item)
+		{
+			Add(item.Key, item.Value);
+		}
+
+		public bool Contains(KeyValuePair<TKey, TValue> item)
+		{
+			return InnerDict.Contains(item);
+		}
+
+		public void CopyTo(KeyValuePair<TKey, TValue>[] array, int arrayIndex)
+		{
+			InnerDict.CopyTo(array, arrayIndex);
+		}
+
+		public bool IsReadOnly
+		{
+			get { return InnerDict.IsReadOnly; }
+		}
+
+		public bool Remove(KeyValuePair<TKey, TValue> item)
+		{
+			return Remove(item.Key);
+		}
+
+		public IEnumerator<KeyValuePair<TKey, TValue>> GetEnumerator()
+		{
+			return InnerDict.GetEnumerator();
+		}
+
+		IEnumerator IEnumerable.GetEnumerator()
+		{
+			return InnerDict.GetEnumerator();
+		}
+
+		public IEnumerable ObservedItems
+		{
+			get { return InnerDict.Keys; }
+		}
+	}
+}