diff --git a/README.md b/README.md
index 85d23832..20f1985b 100644
--- a/README.md
+++ b/README.md
@@ -8,8 +8,9 @@
 - Lib package: [![NuGet Badge](https://buildstats.info/nuget/ImTools.dll)](https://www.nuget.org/packages/ImTools.dll)
 - Code package: [![NuGet Badge](https://buildstats.info/nuget/ImTools)](https://www.nuget.org/packages/ImTools)
 
-Fast immutable persistent collections and other data structures 
-with focus on thread-safety without locks.
+Latest stable version is [v2.1.0](https://github.com/dadhi/ImTools/releases/tag/v2.1.0)
+
+Fast and memory-efficient immutable collections and helper data structures.
 
 Split from [DryIoc](https://github.com/dadhi/dryioc).
 
diff --git a/nuspecs/ImTools.nuspec b/nuspecs/ImTools.nuspec
index 52ee5d77..925e5d22 100644
--- a/nuspecs/ImTools.nuspec
+++ b/nuspecs/ImTools.nuspec
@@ -17,22 +17,10 @@
         <tags>FP Performance Simple Functional Immutable Persistent Map Avl 2-3-4 Self Balanced Tree Dictionary Thread-safe Functional Atomic Ref Algebraic Discriminated Union SumType</tags>
         <releaseNotes>
 <![CDATA[
-        ## v2.1.0 Feature release
-        
-        - added: ImMap234 based on 2-3-4 tree #32
+## v2.1.0 Feature release
 
-        ## v2.0.0 Major feature release
+- Added fast and more memory efficient Experimental.ImMap234 implementing 2-3-4 tree (#32)
 
-        ### Highlights
-
-        - Faster and less allocative ImMap and ImHashMap with more methods (plus bucketed ImMapSlots and ImHashMapSlots variants)
-        - Algebraic sum-type aka descriminated union and one-liner records - Union<TUnion, T1..N>, Box<TBox, T>, Item<TItem, T>
-        - GrowingList<T>, ImZipper<T>, StackPool<T>, Unit, Fun extensions with forward pipe operators
-        - Ref.Swap now accepts state to use closure-less lambdas with less allocations
-
-        ### Details
-            
-        https://github.com/dadhi/ImTools/milestone/2
 ]]>
         </releaseNotes>
         <contentFiles>
diff --git a/src/ImTools/ImTools.Experimental.cs b/src/ImTools/ImTools.Experimental.cs
index c8d88e2d..eab233c5 100644
--- a/src/ImTools/ImTools.Experimental.cs
+++ b/src/ImTools/ImTools.Experimental.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
+using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Threading;
 
@@ -1951,8 +1952,11 @@ protected virtual ImMap234<V> AddOrKeepOrSplitEntry(int key, ref Entry entry, ou
         /// <summary>Lookup for the entry, if not found returns `null`. You can define other Lookup methods on top of it.</summary>
         public virtual Entry GetEntryOrDefault(int key) => null;
 
-        /// <summary>Folds</summary>
-        public virtual S Fold<S>(S state, Func<Entry, S, S> reduce, ImMap234<V>[] parentStack = null) => state;
+        /// <summary>Fold to fold</summary>
+        public virtual S Fold<S>(S state, Func<Entry, S, S> reduce) => state;
+
+        /// <summary>Enumerable</summary>
+        public virtual IEnumerable<Entry> Enumerate() => Enumerable.Empty<Entry>();
 
         // todo: @feature add SoftRemove
 
@@ -2004,7 +2008,13 @@ public override Entry GetEntryOrDefault(int key) =>
                 key == Key ? this : null;
 
             /// <inheritdoc />
-            public override S Fold<S>(S state, Func<Entry, S, S> reduce, ImMap234<V>[] parentStack = null) => reduce(this, state);
+            public override S Fold<S>(S state, Func<Entry, S, S> reduce) => reduce(this, state);
+
+            /// <inheritdoc />
+            public override IEnumerable<Entry> Enumerate()
+            {
+                yield return this;
+            }
         }
 
         /// <summary>2 leafs</summary>
@@ -2073,8 +2083,15 @@ public override Entry GetEntryOrDefault(int key) =>
                 null;
 
             /// <inheritdoc />
-            public override S Fold<S>(S state, Func<Entry, S, S> reduce, ImMap234<V>[] parentStack = null) =>
+            public override S Fold<S>(S state, Func<Entry, S, S> reduce) =>
                 reduce(Entry1, reduce(Entry0, state));
+
+            /// <inheritdoc />
+            public override IEnumerable<Entry> Enumerate()
+            {
+                yield return Entry0;
+                yield return Entry1;
+            }
         }
 
         /// <summary>3 leafs</summary>
@@ -2150,8 +2167,16 @@ public override Entry GetEntryOrDefault(int key) =>
                 null;
 
             /// <inheritdoc />
-            public override S Fold<S>(S state, Func<Entry, S, S> reduce, ImMap234<V>[] parentStack = null) =>
+            public override S Fold<S>(S state, Func<Entry, S, S> reduce) =>
                 reduce(Entry2, reduce(Entry1, reduce(Entry0, state)));
+
+            /// <inheritdoc />
+            public override IEnumerable<Entry> Enumerate()
+            {
+                yield return Entry0;
+                yield return Entry1;
+                yield return Entry2;
+            }
         }
 
         /// <summary>3 leafs</summary>
@@ -2260,8 +2285,17 @@ public override Entry GetEntryOrDefault(int key) =>
                 null;
 
             /// <inheritdoc />
-            public override S Fold<S>(S state, Func<Entry, S, S> reduce, ImMap234<V>[] parentStack = null) =>
+            public override S Fold<S>(S state, Func<Entry, S, S> reduce) =>
                 reduce(Entry3, reduce(Entry2, reduce(Entry1, reduce(Entry0, state))));
+
+            /// <inheritdoc />
+            public override IEnumerable<Entry> Enumerate()
+            {
+                yield return Entry0;
+                yield return Entry1;
+                yield return Entry2;
+                yield return Entry3;
+            }
         }
 
         /// <summary>3 leafs</summary>
@@ -2462,8 +2496,18 @@ public override Entry GetEntryOrDefault(int key) =>
                 null;
 
             /// <inheritdoc />
-            public override S Fold<S>(S state, Func<Entry, S, S> reduce, ImMap234<V>[] parentStack = null) =>
+            public override S Fold<S>(S state, Func<Entry, S, S> reduce) =>
                 reduce(Entry4, reduce(Entry3, reduce(Entry2, reduce(Entry1, reduce(Entry0, state)))));
+
+            /// <inheritdoc />
+            public override IEnumerable<Entry> Enumerate()
+            {
+                yield return Entry0;
+                yield return Entry1;
+                yield return Entry2;
+                yield return Entry3;
+                yield return Entry4;
+            }
         }
 
         /// <summary>2 branches - it is never split itself, but may produce Branch3 if the lower branches are split</summary>
@@ -2595,8 +2639,18 @@ public override Entry GetEntryOrDefault(int key) =>
                 Entry0;
 
             /// <inheritdoc />
-            public override S Fold<S>(S state, Func<Entry, S, S> reduce, ImMap234<V>[] parentStack = null) =>
+            public override S Fold<S>(S state, Func<Entry, S, S> reduce) =>
                 Right.Fold(reduce(Entry0, Left.Fold(state, reduce)), reduce);
+
+            /// <inheritdoc />
+            public override IEnumerable<Entry> Enumerate()
+            {
+                foreach (var l in Left.Enumerate())
+                    yield return l;
+                yield return Entry0;
+                foreach (var r in Right.Enumerate())
+                    yield return r;
+            }
         }
 
         /// <summary>3 branches</summary>
@@ -2818,8 +2872,21 @@ public override Entry GetEntryOrDefault(int key) =>
                 key == Entry0.Key ? Entry0 : Entry1;
 
             /// <inheritdoc />
-            public override S Fold<S>(S state, Func<Entry, S, S> reduce, ImMap234<V>[] parentStack = null) =>
+            public override S Fold<S>(S state, Func<Entry, S, S> reduce) =>
                 Right.Fold(reduce(Entry1, Middle.Fold(reduce(Entry0, Left.Fold(state, reduce)), reduce)), reduce);
+
+            /// <inheritdoc />
+            public override IEnumerable<Entry> Enumerate()
+            {
+                foreach (var l in Left.Enumerate())
+                    yield return l;
+                yield return Entry0;
+                foreach (var m in Middle.Enumerate())
+                    yield return m;
+                yield return Entry1;
+                foreach (var r in Right.Enumerate())
+                    yield return r;
+            }
         }
     }
 
diff --git a/src/ImTools/ImTools.csproj b/src/ImTools/ImTools.csproj
index 4e6b2f92..ed8852f3 100644
--- a/src/ImTools/ImTools.csproj
+++ b/src/ImTools/ImTools.csproj
@@ -22,22 +22,9 @@
         <PackageTags>FP Performance Simple Functional Immutable Persistent Map Avl 2-3-4 Self Balanced Tree Dictionary Thread-safe Functional Atomic Ref Algebraic Discriminated Union SumType</PackageTags>
         <PackageReleaseNotes>
 <![CDATA[
-        ## v2.1.0 Feature release
-        
-        - added: ImMap234 based on 2-3-4 tree #32
+## v2.1.0 Feature release
 
-        ## v2.0.0 Major feature release
-
-        ### Highlights
-
-        - Faster and less allocative ImMap and ImHashMap with more methods (plus bucketed ImMapSlots and ImHashMapSlots variants)
-        - Algebraic sum-type aka descriminated union and one-liner records - Union<TUnion, T1..N>, Box<TBox, T>, Item<TItem, T>
-        - GrowingList<T>, ImZipper<T>, StackPool<T>, Unit, Fun extensions with forward pipe operators
-        - Ref.Swap now accepts state to use closure-less lambdas with less allocations
-
-        ### Details
-            
-        https://github.com/dadhi/ImTools/milestone/2
+- Added fast and more memory efficient Experimental.ImMap234 implementing 2-3-4 tree (#32)
 ]]>
     </PackageReleaseNotes>
     </PropertyGroup>
diff --git a/test/ImTools.UnitTests/Experimental.ImMap234Tests.cs b/test/ImTools.UnitTests/Experimental.ImMap234Tests.cs
index addea175..13f85a45 100644
--- a/test/ImTools.UnitTests/Experimental.ImMap234Tests.cs
+++ b/test/ImTools.UnitTests/Experimental.ImMap234Tests.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Linq;
 using NUnit.Framework;
 
 namespace ImTools.Experimental.UnitTests
@@ -44,6 +45,8 @@ public void Adding_keys_from_1_to_10_and_checking_the_tree_shape_on_each_additio
             Assert.AreEqual(5, m.GetValueOrDefault(5));
             Assert.AreEqual(6, m.GetValueOrDefault(6));
 
+            CollectionAssert.AreEqual(Enumerable.Range(1, 6), m.Enumerate().Select(x => x.Value));
+
             m = m.AddOrUpdate(7, 7);
             Assert.IsInstanceOf<ImMap234<int>.Branch2>(m);
             Assert.AreEqual(7, m.GetValueOrDefault(7));
@@ -57,6 +60,8 @@ public void Adding_keys_from_1_to_10_and_checking_the_tree_shape_on_each_additio
 
             m = m.AddOrUpdate(10, 10);
             Assert.AreEqual(10, m.GetValueOrDefault(10));
+
+            CollectionAssert.AreEqual(Enumerable.Range(1, 10), m.Enumerate().Select(x => x.Value));
         }
 
         [Test]