diff --git a/NBToolkit/FilteredChunkManager.cs b/NBToolkit/FilteredChunkManager.cs
new file mode 100644
index 0000000..0fe81ca
--- /dev/null
+++ b/NBToolkit/FilteredChunkManager.cs
@@ -0,0 +1,214 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Text;
+using Substrate;
+
+namespace NBToolkit
+{
+    class FilteredChunkManager : IChunkManager, IEnumerable<ChunkRef>
+    {
+        private IChunkManager _cm;
+        private IChunkFilter _filter;
+
+        public FilteredChunkManager (IChunkManager cm, IChunkFilter filter)
+        {
+            _cm = cm;
+            _filter = filter;
+        }
+
+
+        #region IEnumerable<ChunkRef> Members
+
+        public IEnumerator<ChunkRef> GetEnumerator ()
+        {
+            return new ChunkEnumerator(_cm, _filter);
+        }
+
+        #endregion
+
+
+        #region IEnumerable Members
+
+        IEnumerator IEnumerable.GetEnumerator ()
+        {
+            return new ChunkEnumerator(_cm, _filter);
+        }
+
+        #endregion
+
+
+        public class ChunkEnumerator : IEnumerator<ChunkRef>
+        {
+            private IChunkManager _cm;
+            private IChunkFilter _filter;
+
+            private IEnumerator<ChunkRef> _enum;
+
+            public ChunkEnumerator (IChunkManager cm, IChunkFilter filter)
+            {
+                _cm = cm;
+                _filter = filter;
+                _enum = _cm.GetEnumerator();
+            }
+
+
+            #region IEnumerator<ChunkRef> Members
+
+            public ChunkRef Current
+            {
+                get { return _enum.Current; }
+            }
+
+            #endregion
+
+
+            #region IDisposable Members
+
+            public void Dispose ()
+            {
+            }
+
+            #endregion
+
+
+            #region IEnumerator Members
+
+            object IEnumerator.Current
+            {
+                get { return _enum.Current; }
+            }
+
+            public bool MoveNext ()
+            {
+                while (true) {
+                    if (_enum.MoveNext() == false) {
+                        return false;
+                    }
+
+                    // Filter by coordinates
+                    if (_filter.InvertXZ) {
+                        if (_filter.XAboveEq != null && _filter.XBelowEq != null &&
+                            _filter.ZAboveEq != null && _filter.ZBelowEq != null &&
+                            Current.X >= _filter.XAboveEq && Current.X <= _filter.XBelowEq &&
+                            Current.Z >= _filter.ZAboveEq && Current.Z <= _filter.ZBelowEq) {
+                            continue;
+                        }
+                    }
+                    else {
+                        if (_filter.XAboveEq != null && Current.X < _filter.XAboveEq) {
+                            continue;
+                        }
+                        if (_filter.XBelowEq != null && Current.X > _filter.XBelowEq) {
+                            continue;
+                        }
+                        if (_filter.ZAboveEq != null && Current.Z < _filter.ZAboveEq) {
+                            continue;
+                        }
+                        if (_filter.ZBelowEq != null && Current.Z > _filter.ZBelowEq) {
+                            continue;
+                        }
+                    }
+
+                    // Filter out chunks that do not contain required blocks (included list)
+                    if (_filter.IncludedBlockCount > 0) {
+                        int matchCount = 0;
+                        foreach (int block in _filter.IncludedBlocks) {
+                            if (Current.CountBlockID(block) > 0) {
+                                matchCount++;
+                            }
+                        }
+
+                        if (_filter.IncludeMatchAny && matchCount == 0) {
+                            continue;
+                        }
+                        if (_filter.IncludeMatchAll && matchCount != _filter.IncludedBlockCount) {
+                            continue;
+                        }
+                    }
+
+                    // Filter out chunks that contain forbiddon blocks (excluded list)
+                    if (_filter.ExcludedBlockCount > 0) {
+                        int matchCount = 0;
+                        foreach (int block in _filter.ExcludedBlocks) {
+                            if (Current.CountBlockID(block) > 0) {
+                                matchCount++;
+                            }
+                        }
+
+                        if (_filter.ExcludeMatchAny && matchCount > 0) {
+                            continue;
+                        }
+                        if (_filter.ExcludeMatchAll && matchCount == _filter.ExcludedBlockCount) {
+                            continue;
+                        }
+                    }
+
+                    return true;
+                }
+            }
+
+            public void Reset ()
+            {
+                _enum.Reset();
+            }
+
+            #endregion
+        }
+
+
+        #region IChunkContainer Members
+
+        public int ChunkGlobalX (int cx)
+        {
+            return _cm.ChunkGlobalX(cx);
+        }
+
+        public int ChunkGlobalZ (int cz)
+        {
+            return _cm.ChunkGlobalZ(cz);
+        }
+
+        public int ChunkLocalX (int cx)
+        {
+            return _cm.ChunkLocalX(cx);
+        }
+
+        public int ChunkLocalZ (int cz)
+        {
+            return _cm.ChunkLocalZ(cz);
+        }
+
+        public Chunk GetChunk (int cx, int cz)
+        {
+            return _cm.GetChunk(cx, cz);
+        }
+
+        public ChunkRef GetChunkRef (int cx, int cz)
+        {
+            return _cm.GetChunkRef(cx, cz);
+        }
+
+        public bool ChunkExists (int cx, int cz)
+        {
+            return _cm.ChunkExists(cx, cz);
+        }
+
+        public bool DeleteChunk (int cx, int cz)
+        {
+            return _cm.DeleteChunk(cx, cz);
+        }
+
+        public int Save ()
+        {
+            return _cm.Save();
+        }
+
+        public bool SaveChunk (Chunk chunk)
+        {
+            return _cm.SaveChunk(chunk);
+        }
+
+        #endregion
+    }
+}
diff --git a/NBToolkit/Oregen.cs b/NBToolkit/Oregen.cs
index 150128f..b67931a 100644
--- a/NBToolkit/Oregen.cs
+++ b/NBToolkit/Oregen.cs
@@ -183,7 +183,7 @@ namespace NBToolkit
         {
             World world = new World(opt.OPT_WORLD);
 
-            ChunkManager cm = world.GetChunkManager() as ChunkManager;
+            IChunkManager cm = world.GetChunkManager();
             FilteredChunkManager fcm = new FilteredChunkManager(cm, opt.GetChunkFilter());
 
             int affectedChunks = 0;
diff --git a/Substrate/SubstrateCS/Source/ChunkFile.cs b/Substrate/SubstrateCS/Source/ChunkFile.cs
index 5695a2e..07dd937 100644
--- a/Substrate/SubstrateCS/Source/ChunkFile.cs
+++ b/Substrate/SubstrateCS/Source/ChunkFile.cs
@@ -6,6 +6,8 @@ using Ionic.Zlib;
 
 namespace Substrate
 {
+    using Utility;
+
     public class ChunkFile : NBTFile
     {
         public ChunkFile (string path)
@@ -16,21 +18,23 @@ namespace Substrate
         public ChunkFile (string path, int cx, int cz)
             : base("")
         {
-            string cx64 = Base64(cx);
-            string cz64 = Base64(cz);
+            string cx64 = Base36.Encode(cx);
+            string cz64 = Base36.Encode(cz);
             string file = "c." + cx64 + "." + cz64 + ".dat";
 
-            string dir1 = Base64(cx % 64);
-            string dir2 = Base64(cz % 64);
+            while (cx < 0) {
+                cx += (64 * 64);
+            }
+            while (cz < 0) {
+                cz += (64 * 64);
+            }
+
+            string dir1 = Base36.Encode(cx % 64);
+            string dir2 = Base36.Encode(cz % 64);
 
             _filename = Path.Combine(path, dir1);
             _filename = Path.Combine(_filename, dir2);
             _filename = Path.Combine(_filename, file);
         }
-
-        private string Base64 (int val)
-        {
-            return Convert.ToBase64String(System.Text.Encoding.UTF8.GetBytes(val.ToString()));
-        }
     }
 }
diff --git a/Substrate/SubstrateCS/Source/ChunkFileManager.cs b/Substrate/SubstrateCS/Source/ChunkFileManager.cs
index 2c84706..48a8bbf 100644
--- a/Substrate/SubstrateCS/Source/ChunkFileManager.cs
+++ b/Substrate/SubstrateCS/Source/ChunkFileManager.cs
@@ -1,11 +1,14 @@
 using System;
+using System.Collections;
 using System.Collections.Generic;
 using System.Text;
+using System.Text.RegularExpressions;
 using System.IO;
 
 namespace Substrate
 {
     using NBT;
+    using Utility;
 
     public class ChunkFileManager : IChunkManager, IChunkCache
     {
@@ -14,6 +17,11 @@ namespace Substrate
         protected Dictionary<ChunkKey, WeakReference> _cache;
         protected Dictionary<ChunkKey, ChunkRef> _dirty;
 
+        public string ChunkPath
+        {
+            get { return _mapPath; }
+        }
+
         public ChunkFileManager (string mapDir)
         {
             _mapPath = mapDir;
@@ -189,7 +197,7 @@ namespace Substrate
 
         public IEnumerator<ChunkRef> GetEnumerator ()
         {
-            return null;
+            return new ChunkEnumerator(this);
         }
 
         #endregion
@@ -198,9 +206,156 @@ namespace Substrate
 
         System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator ()
         {
-            return null;
+            return new ChunkEnumerator(this);
         }
 
         #endregion
+
+
+        public class ChunkEnumerator : IEnumerator<ChunkRef>
+        {
+            protected ChunkFileManager _cm;
+            protected Queue<string> _tld;
+            protected Queue<string> _sld;
+            protected Queue<ChunkRef> _chunks;
+
+            private string _curtld;
+            private string _cursld;
+            private ChunkRef _curchunk;
+
+            public ChunkEnumerator (ChunkFileManager cfm)
+            {
+                _cm = cfm;
+
+                if (!Directory.Exists(_cm.ChunkPath)) {
+                    throw new DirectoryNotFoundException();
+                }
+
+                Reset();
+            }
+
+            private bool MoveNextTLD ()
+            {
+                if (_tld.Count == 0) {
+                    return false;
+                }
+
+                _curtld = _tld.Dequeue();
+
+                //string path = Path.Combine(_cm.ChunkPath, _curtld);
+
+                string[] files = Directory.GetDirectories(_curtld);
+                foreach (string file in files) {
+                    _sld.Enqueue(file);
+                }
+
+                return true;
+            }
+
+            public bool MoveNextSLD ()
+            {
+                while (_sld.Count == 0) {
+                    if (MoveNextTLD() == false) {
+                        return false;
+                    }
+                }
+
+                _cursld = _sld.Dequeue();
+
+                //string path = Path.Combine(_cm.ChunkPath, _curtld);
+                //path = Path.Combine(path, _cursld);
+
+                string[] files = Directory.GetFiles(_cursld);
+                foreach (string file in files) {
+                    int x;
+                    int z;
+
+                    string basename = Path.GetFileName(file);
+
+                    if (!ParseFileName(basename, out x, out z)) {
+                        continue;
+                    }
+
+                    ChunkRef cref = _cm.GetChunkRef(x, z);
+                    if (cref != null) {
+                        _chunks.Enqueue(cref);
+                    }
+                }
+
+                return true;
+            }
+
+            public bool MoveNext ()
+            {
+                while (_chunks.Count == 0) {
+                    if (MoveNextSLD() == false) {
+                        return false;
+                    }
+                }
+
+                _curchunk = _chunks.Dequeue();
+                return true;
+            }
+
+            public void Reset ()
+            {
+                _curchunk = null;
+
+                _tld = new Queue<string>();
+                _sld = new Queue<string>();
+                _chunks = new Queue<ChunkRef>();
+
+                string[] files = Directory.GetDirectories(_cm.ChunkPath);
+                foreach (string file in files) {
+                    _tld.Enqueue(file);
+                }
+            }
+
+            void IDisposable.Dispose () { }
+
+            object IEnumerator.Current
+            {
+                get
+                {
+                    return Current;
+                }
+            }
+
+            ChunkRef IEnumerator<ChunkRef>.Current
+            {
+                get
+                {
+                    return Current;
+                }
+            }
+
+            public ChunkRef Current
+            {
+                get
+                {
+                    if (_curchunk == null) {
+                        throw new InvalidOperationException();
+                    }
+                    return _curchunk;
+                }
+            }
+
+            private bool ParseFileName (string filename, out int x, out int z)
+            {
+                x = 0;
+                z = 0;
+
+                Match match = _namePattern.Match(filename);
+                if (!match.Success) {
+                    return false;
+                }
+
+                x = (int)Base36.Decode(match.Groups[1].Value);
+                z = (int)Base36.Decode(match.Groups[2].Value);
+                return true;
+            }
+
+            protected static Regex _namePattern = new Regex("c\\.(-?[0-9a-zA-Z]+)\\.(-?[0-9a-zA-Z]+)\\.dat$");
+        }
     }
 }
diff --git a/Substrate/SubstrateCS/Source/ChunkManager.cs b/Substrate/SubstrateCS/Source/ChunkManager.cs
index 06d2364..be4c243 100644
--- a/Substrate/SubstrateCS/Source/ChunkManager.cs
+++ b/Substrate/SubstrateCS/Source/ChunkManager.cs
@@ -209,8 +209,6 @@ namespace Substrate
             private int _x = 0;
             private int _z = -1;
 
-            //protected RegionEnumerator _enum = null;
-
             public ChunkEnumerator (ChunkManager cm)
             {
                 _cm = cm;
diff --git a/Substrate/SubstrateCS/Source/NBTFile.cs b/Substrate/SubstrateCS/Source/NBTFile.cs
index 5a89721..fc54727 100644
--- a/Substrate/SubstrateCS/Source/NBTFile.cs
+++ b/Substrate/SubstrateCS/Source/NBTFile.cs
@@ -28,7 +28,7 @@ namespace Substrate
             return true;
         }
 
-        public Stream GetDataInputStream ()
+        public virtual Stream GetDataInputStream ()
         {
             FileStream fstr = new FileStream(_filename, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
 
@@ -43,9 +43,9 @@ namespace Substrate
             return new GZipStream(new MemoryStream(data), CompressionMode.Decompress);
         }
 
-        public Stream GetDataOutputStream ()
+        public virtual Stream GetDataOutputStream ()
         {
-            return new ZlibStream(new NBTBuffer(this), CompressionMode.Compress);
+            return new GZipStream(new NBTBuffer(this), CompressionMode.Compress);
         }
 
         class NBTBuffer : MemoryStream
diff --git a/Substrate/SubstrateCS/Source/Utility/Base.cs b/Substrate/SubstrateCS/Source/Utility/Base.cs
new file mode 100644
index 0000000..ef2f373
--- /dev/null
+++ b/Substrate/SubstrateCS/Source/Utility/Base.cs
@@ -0,0 +1,63 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Substrate.Utility
+{
+    public static class Base36
+    {
+        private const string _alphabet = "0123456789abcdefghijklmnopqrstuvwxyz";
+
+        public static string Encode (long input)
+        {
+            if (input == 0) {
+                return "0";
+            }
+
+            bool neg = (input < 0);
+            if (neg) {
+                input *= -1;
+            }
+
+            Stack<char> result = new Stack<char>();
+            while (input != 0) {
+                result.Push(_alphabet[(int)(input % 36)]);
+                input /= 36;
+            }
+
+            string ret = new string(result.ToArray());
+            if (neg) {
+                ret = '-' + ret;
+            }
+
+            return ret;
+        }
+
+        public static long Decode (string input)
+        {
+            if (input.Length == 0) {
+                throw new ArgumentOutOfRangeException("input", input);
+            }
+
+            bool neg = false;
+            if (input[0] == '-') {
+                neg = true;
+                input = input.Substring(1);
+            }
+
+            input = input.ToLower();
+            long result = 0;
+
+            int pos = 0;
+            for (int i = input.Length - 1; i >= 0; i--) {
+                result += _alphabet.IndexOf(input[i]) * (long)Math.Pow(36, pos);
+                pos++;
+            }
+
+            if (neg) {
+                result *= -1;
+            }
+            return result;
+        }
+    }
+}
diff --git a/Substrate/SubstrateCS/Substrate.csproj b/Substrate/SubstrateCS/Substrate.csproj
index c748430..72a9ea2 100644
--- a/Substrate/SubstrateCS/Substrate.csproj
+++ b/Substrate/SubstrateCS/Substrate.csproj
@@ -60,6 +60,7 @@
     </Reference>
     <Reference Include="System" />
     <Reference Include="System.Data" />
+    <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
     <Compile Include="Source\Level.cs" />
@@ -128,6 +129,7 @@
     <Compile Include="Source\TileEntities\TileEntityTrap.cs" />
     <Compile Include="Source\TileEntity.cs" />
     <Compile Include="Source\TileEntityFactory.cs" />
+    <Compile Include="Source\Utility\Base.cs" />
     <Compile Include="Source\Utility\Interface.cs" />
     <Compile Include="Source\Utility\NibbleArray.cs" />
     <Compile Include="Source\World.cs" />